Semiconductor device and power feed system

This nonprovisional application is based on Japanese Patent Applications Nos. 2016-014671, 2016-014660, and 2016-189574 filed with the Japan Patent Office on Jan. 28, 2016, Jan. 28, 2016 and Sep. 28, 2016, respectively, the entire contents of which are hereby incorporated by reference.

The present disclosure relates to a power supply circuit which generates an output voltage to be supplied to a universal serial bus (USB) device.

Description of the Background Art

A configuration in which electric power is supplied to a USB device through a USB connector (also referred to as USB power feed) has conventionally been known (Japanese Patent Laying-Open No. 2012-123673).

An output voltage supplied to a conventional USB device has been fixed (by way of example, 5 V).

Equipment having a USB connector has recently increased and each piece of equipment is expected to be fed power through a USB.

In this connection, since requested electric power is different for each piece of equipment, an output voltage on a power feed side is not fixed but should be variable, and various protection functions are provided to ensure safety of power feed at a high voltage.

In case of a failure, there has been no means for holding a state of the failure and it has not been possible to perform an operation appropriate in accordance with a state.

The present disclosure was made to solve the problems above, and an object is to provide a semiconductor device and a power feed system which can perform an operation appropriate in accordance with a state of a power supply circuit.

Other objects and novel features will become apparent from the description herein and the accompanying drawings.

According to one example, a semiconductor device includes a power supply circuit which generates an output voltage to be supplied to a USB device connected to a USB connector, a sensing circuit which senses the output voltage or an output state of the power supply circuit, a control circuit which controls the power supply circuit, and a register which stores an output set voltage value associated with the power supply circuit or various types of information. The control circuit outputs a notification signal based on a result of sensing by the sensing circuit to the outside.

The foregoing and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.

FIG. 1 is a diagram illustrating a configuration of a power supply control system 1 based on a first embodiment.

FIG. 2 is a diagram illustrating a configuration of a power feed device 10 based on the first embodiment.

FIG. 3 is a diagram illustrating a configuration of a protection circuit 22 based on the first embodiment.

FIG. 4 is a sequence diagram when a voltage level is regulated from an old voltage to a new voltage in power supply control system 1 based on the first embodiment.

FIG. 5 is a sequence diagram for illustrating an operation at the time of a system error in power supply control system 1 based on the first embodiment.

FIG. 6 is a sequence diagram for illustrating an operation in power supply control system 1 based on the first embodiment when a temperature is abnormal.

FIG. 7 is a sequence diagram for illustrating an operation in power supply control system 1 based on the first embodiment when a voltage is abnormal.

FIG. 8 is a flowchart when processing for regulating a voltage level in a power delivery control unit 16 based on the first embodiment is performed.

FIG. 9 is a flowchart illustrating an operation for regulating a voltage in a power delivery power supply unit 14 based on the first embodiment.

FIG. 10 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the first embodiment when a temperature is abnormal.

FIG. 11 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the first embodiment when a temperature is abnormal.

FIG. 12 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the first embodiment when a voltage is abnormal.

FIG. 13 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the first embodiment when a voltage is abnormal.

FIG. 14 is a sequence diagram for illustrating an operation in power supply control system 1 based on a modification of the first embodiment when a temperature is abnormal.

FIG. 15 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the modification of the first embodiment when a temperature is abnormal.

FIG. 16 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the modification of the first embodiment when a temperature is abnormal.

FIG. 17 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the modification of the first embodiment when a voltage is abnormal.

FIG. 18 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the modification of the first embodiment when a voltage is abnormal.

FIG. 19 is a diagram illustrating a configuration of power supply control system 1 based on a second embodiment.

FIG. 20 is a diagram illustrating a configuration of a power feed device 10 # based on the second embodiment.

FIG. 21 is a diagram illustrating a configuration of a voltage determination circuit 23 based on the second embodiment.

FIG. 22 is a sequence diagram when a voltage level is regulated from an old voltage to a new voltage in a power supply control system 1 # based on the second embodiment.

FIGS. 23A and 23B are diagrams illustrating an operation for changing a voltage in a power supply circuit 20 based on the second embodiment.

FIG. 24 is a sequence diagram illustrating an operation in an abnormal condition in regulation of a voltage level in power supply control system 1 # based on the second embodiment.

FIG. 25 is a flowchart when processing for regulating a voltage level in a power delivery control unit 16 # based on the second embodiment is performed.

FIG. 26 is a flowchart illustrating an operation for regulating a voltage of a power delivery power supply unit 14 # based on the second embodiment.

FIG. 27 is a sequence diagram illustrating a normal operation during power feed from power delivery power supply unit 14 # to a power reception device 100 based on the second embodiment.

FIG. 28 is a sequence diagram illustrating an operation when an abnormal condition occurs during power feed from power delivery power supply unit 14 # to power reception device 100 based on the second embodiment.

FIG. 29 is a flowchart illustrating an operation of power delivery control unit 16 # based on the second embodiment in issuance of a timer reset command.

FIG. 30 is a flowchart illustrating an operation of power delivery power supply unit 14 # based on the second embodiment in issuance of the timer reset command.

FIG. 31 is a diagram illustrating a configuration of a power feed device 11 based on a third embodiment.

FIG. 32 is a flowchart when processing for regulating a voltage level in each of power delivery control units 16 #A and 16 #B based on the third embodiment is performed.

FIG. 33 is a flowchart illustrating a sub routine process for checking a voltage request in power feed in step S 4 #.

FIG. 34 is a diagram illustrating a configuration of a power feed device 11 # based on a fourth embodiment.

An embodiment will be described in detail with reference to the drawings. The same or corresponding elements in the drawings have the same reference characters allotted and description thereof will not be repeated.

First Embodiment

<A. Overall Configuration>

<a1. Configuration of Power Supply Control System 1 >

FIG. 1 is a diagram illustrating a configuration of a power supply control system 1 based on a first embodiment.

Referring to FIG. 1 , power supply control system 1 includes a power feed device (power feed control device) 10 and a power reception device 100 .

Power reception device 100 has a USB connector 102 , a power delivery control unit 104 , a USB data control unit 106 , and an application processing unit 108 .

Power feed device 10 has a USB connector 12 , a power delivery power supply v 14 , a power delivery control unit 16 , and a USB data control unit 18 .

USB connector 12 and USB connector 102 are connected to each other through a USB bus 110 .

USB bus 110 includes a power supply line VL, a data line DL, and a control data line CL.

Power reception device 100 receives supply of a voltage from power feed device 10 through power supply line VL when USB connector 102 and USB connector 12 are connected to each other through USB bus 110 .

Power reception device 100 and power feed device 10 are configured to be able to supply and receive data to and from each other through data line DL when USB connector 102 and USB connector 12 are connected to each other through USB bus 110 . Data is supplied and received through data line DL between USB data control unit 18 of power feed device 10 and USB data control unit 106 of power reception device 100 .

Power reception device 100 and power feed device 10 are configured to be able to supply and receive control data to and from each other through control data line CL when USB connector 102 and USB connector 12 are connected to each other through USB bus 110 . Control data is supplied and received through control data line CL between power delivery control unit 16 of power feed device 10 and power delivery control unit 104 of power reception device 100 .

Power delivery control unit 16 controls power delivery power supply unit 14 . Specifically, power delivery control unit 16 indicates setting of a level of a voltage to be supplied to power delivery power supply unit 14 . In the present example, power delivery power supply unit 14 is a power supply device which can variably regulate a level of a voltage to be supplied to the outside upon receiving input of an alternating current (AC) voltage or a direct current (DC) voltage as a power supply input. By way of example, a voltage level can be regulated in a range from 5 V to 20 V. Power delivery control unit 16 communicates with power reception device 100 through control data line CL and controls power delivery power supply unit 14 based on voltage data from power reception device 100 .

Power delivery control unit 104 has electric power necessary for each unit supplied, upon receiving supply of a voltage from power feed device 10 through power supply line VL. Power delivery control unit 104 communicates with power delivery control unit 16 through control data line CL. Specifically, power delivery control unit 104 transmits voltage data on a voltage necessary for power reception device 100 to power delivery control unit 16 through control data line CL.

USB data control unit 106 supplies and receives data to and from USB data control unit 18 of power feed device 10 connected through USB bus 110 .

Application processing unit 108 is a unit executing a prescribed application. As a central processing unit (CPU) executes a program, a prescribed application is executed. USB data control unit 106 transfers data from equipment connected through USB connector 102 to application processing unit 108 as necessary and transmits data from application processing unit 108 to equipment connected through USB connector 102 .

<a2. Configuration of Power Feed Device 10 >

FIG. 2 is a diagram illustrating a configuration of power feed device 10 based on the first embodiment.

Referring to FIG. 2 , power feed device 10 includes USB connector 12 , power delivery power supply unit 14 , and power delivery control unit 16 . USB data control unit 18 is not shown.

Power delivery power supply unit 14 includes a power supply circuit 20 , a protection circuit 22 , a control circuit 24 , a register 26 , and an interface 28 .

Power supply circuit 20 generates a power supply voltage to be supplied to the outside, upon receiving input of an alternating current (AC) voltage or a direct current (DC) voltage as a power supply input. Power supply circuit 20 supplies a generated power supply voltage to another USB device through USB connector 12 connected to power supply line VL.

Protection circuit 22 is a circuit for ensuring safety of power delivery power supply unit 14 . For example, when a junction temperature of power supply circuit 20 increases, the circuit is activated and notifies control circuit 24 of an abnormal condition. Control circuit 24 instructs power supply circuit 20 to stop power supply based on the notification.

Control circuit 24 controls entire power delivery power supply unit 14 .

Interface 28 is connected to control circuit 24 . Interface 28 transmits data from control circuit 24 to power delivery control unit 16 , or receives data from power delivery control unit 16 and transfers the data to control circuit 24 .

Register 26 stores information on power delivery power supply unit 14 .

Specifically, register 26 includes a voltage setting region 26 A where information on setting of a power supply voltage of power supply circuit 20 is stored and a status storage region 26 B where information on an internal state of power supply circuit 20 is stored.

Control circuit 24 writes data into register 26 as necessary and reads data stored in register 26 and transmits the data to power delivery control unit 16 through interface 28 .

Power delivery control unit 16 includes an interface 30 , a communication interface 32 , a microcomputer 34 , and a memory 36 .

Microcomputer 34 controls entire power delivery control unit 16 .

Memory 36 stores various programs. Microcomputer 34 performs a prescribed function based on a program stored in memory 36 .

Interface 30 is used for supplying and receiving data to and from power delivery power supply unit 14 .

Interface 30 is connected to microcomputer 34 . Interface 30 transmits data from microcomputer 34 to power delivery power supply unit 14 or receives data from power delivery power supply unit 14 and transfers the data to microcomputer 34 .

Communication interface 32 is an interface for establishing power delivery control communication with another USB device through USB connector 12 connected to control data line CL.

Communication interface 32 is connected to microcomputer 34 . Communication interface 32 transmits control data from microcomputer 34 to another USB device (power reception device 100 ) or receives control data from another USB device (power reception device 100 ) and transfers the control data to microcomputer 34 .

<a3. Configuration of Protection Circuit 22 >

FIG. 3 is a diagram illustrating a configuration of protection circuit 22 based on the first embodiment.

Referring to FIG. 3 , protection circuit 22 includes a temperature abnormal condition determination circuit 22 A determining whether or not a temperature of power supply circuit 20 is normal and a voltage abnormal condition determination circuit 22 B determining whether or not a power supply voltage of power supply circuit 20 is normal.

Temperature abnormal condition determination circuit 22 A includes a comparator 120 and a temperature detector 122 .

Temperature detector 122 outputs a voltage in accordance with a temperature.

Comparator 120 compares a voltage from temperature detector 122 with a reference value and outputs a control signal based on a result of comparison to control circuit 24 .

Temperature detector 122 is used for detecting a junction temperature of power supply circuit 20 by way of example.

Specifically, when a voltage from temperature detector 122 has exceeded the reference value, comparator 120 outputs a control signal (at the “H” level) indicating that fact to control circuit 24 . The reference value can be set to a value ensuring safety of power supply circuit 20 .

Control circuit 24 controls on/off of an operation of power supply circuit 20 based on a control signal from comparator 120 . Specifically, control circuit 24 stops an operation for power supply by power supply circuit 20 in response to an input of the control signal (at the “H” level) from comparator 120 . Control circuit 24 has an operation for power supply by power supply circuit 20 continued when a control signal (at the “L” level) is input from comparator 120 .

Voltage abnormal condition determination circuit 22 B includes a comparator 130 and a voltage detection circuit 132 .

Voltage detection circuit 132 detects a voltage from power supply circuit 20 .

Comparator 130 compares a voltage from voltage detection circuit 132 with a reference value and outputs a control signal based on a result of comparison to control circuit 24 .

Specifically, when a voltage from voltage detection circuit 132 has exceeded the reference value, comparator 130 outputs a control signal (at the “H” level) indicating that fact to control circuit 24 . The reference value can be set to a value ensuring safety of power supply circuit 20 .

Control circuit 24 controls on/off of an operation of power supply circuit 20 based on a control signal from comparator 130 . Specifically, control circuit 24 stops an operation for power supply by power supply circuit 20 in response to an input of the control signal (at the “H” level”) from comparator 130 . Control circuit 24 has an operation for power supply by power supply circuit 20 continued when a control signal (at the “L” level) is input from comparator 130 .

<B. Voltage Control Sequence>

<b1. Regulation of Voltage Level>

FIG. 4 is a sequence diagram when a voltage level is regulated from an old voltage to a new voltage in power supply control system 1 based on the first embodiment.

Referring to FIG. 4 , power reception device 100 which is a consumption side issues a voltage request (sequence sq1). Power delivery control unit 104 issues a request to power delivery control unit 16 for a voltage necessary for power reception device 100 .

Power delivery control unit 16 determines whether or not power can be fed in response to the voltage request from power reception device 100 . It checks whether or not a requested value of the voltage level is within a power feed allowable range. When it is determined that the value of the requested voltage level is within the power feed allowable range, a notification that the voltage is permitted is given to power delivery control unit 104 (sequence sq2).

Power reception device 100 which is the consumption side accepts permission (sequence sq3).

Power reception device 100 is thus set to a stand-by state and waits for an instruction indicating being ready from a power feed side.

Power delivery control unit 104 outputs a notification that permission is accepted to power feed device 10 , upon receiving the notification that the voltage is permitted from power feed device 10 which is a supply side.

In response, power feed device 10 starts a voltage regulation operation on a side of power feed device 10 .

Power delivery control unit 16 gives a voltage instruction to power delivery power supply unit 14 (sequence sq4).

Upon receiving the voltage instruction, power delivery power supply unit 14 changes a voltage (sequence sq5). Control circuit 24 of power delivery power supply unit 14 has register 26 store information on a voltage to be supplied in voltage setting region 26 A.

Power feed device 10 which is the power feed side notifies power reception device 100 which is the consumption side that a voltage is ready after lapse of a prescribed period since power delivery control unit 16 gives the voltage instruction to power delivery power supply unit 14 (sequence sq6). The prescribed period is set in advance to a period equal to or longer than a period necessary until change to a new voltage is made from issuance of the voltage instruction to power delivery power supply unit 14 .

Power reception device 100 which is the consumption side accepts the voltage being ready, upon receiving a notification indicating that a voltage is ready from power feed device 10 (sequence sq7).

Power reception device 100 is thus set from the stand-by state to a current consumption state and driven upon receiving supply of a voltage from power feed device 10 .

<b2. Case of System Error>

FIG. 5 is a sequence diagram for illustrating an operation at the time of a system error in power supply control system 1 based on the first embodiment.

Referring to FIG. 5 , when a system error (for example, a communication error) against power reception device 100 occurs, power feed device 10 which is the power feed side gives a hard reset notification (sequence sq10). Power delivery control unit 16 gives a hard reset notification to power delivery control unit 104 .

Power reception device 100 which is the consumption side accepts the hard reset notification (sequence sq11). Power reception device 100 is thus set to the stand-by state in which supply of a voltage from power feed device 10 is awaited.

Then, power feed device 10 which is the power feed side gives a reset instruction (sequence sq12). Power delivery control unit 16 instructs power delivery power supply unit 14 to reset.

Power delivery power supply unit 14 changes a voltage upon receiving a reset instruction from power delivery control unit 16 (sequence sq13). Control circuit 24 of power delivery power supply unit 14 sets a voltage from power supply circuit 20 to 0 V upon receiving the reset instruction.

Then, power delivery control unit 16 gives a voltage instruction to power delivery power supply unit 14 (sequence sq14).

Power delivery power supply unit 14 changes a voltage upon receiving the voltage instruction (sequence sq15). Control circuit 24 of power delivery power supply unit 14 has register 26 store information on a voltage to be supplied in voltage setting region 26 A. Specifically, control circuit 24 sets an initial value in voltage setting region 26 A of register 26 as information on a voltage to be supplied. In the present example, 5 V is set.

<b3. Case of Abnormal Temperature>

FIG. 6 is a sequence diagram for illustrating an operation in power supply control system 1 based on the first embodiment when a temperature is abnormal.

Referring to FIG. 6 , it is assumed that a temperature is abnormal in power delivery power supply unit 14 (sequence sq20). Specifically, temperature abnormal condition determination circuit 22 A outputs a control signal (at the “H” level”) to control circuit 24 in accordance with a junction temperature of power supply circuit 20 . Control circuit 24 carries out power supply off control of power supply circuit 20 and has power supply circuit 20 stop an operation for power supply. Specifically, 0 V is set.

Then, in power delivery power supply unit 14 , information is written in a register (sequence sq21). Specifically, control circuit 24 writes information on an abnormal temperature in status storage region 26 B of register 26 .

Power delivery control unit 16 reads information from register 26 (sequence sq22). Information is read in response to an instruction from power delivery control unit 16 to power delivery power supply unit 14 every prescribed period.

Power delivery control unit 16 obtains information from register 26 , confirms that a temperature is abnormal, and gives a hard reset notification (sequence sq23). Power delivery control unit 16 gives a hard reset notification to power delivery control unit 104 .

Power reception device 100 which is the consumption side accepts the hard reset notification (sequence sq24). Power reception device 100 is thus set to the stand-by state in which voltage supply from power feed device 10 is awaited.

Then, it is assumed that a temperature has returned to a normal condition in power delivery power supply unit 14 (sequence sq25).

Then, in power delivery power supply unit 14 , information is written in register 26 (sequence sq26). Specifically, control circuit 24 writes information on a temperature into status storage region 26 B of register 26 . In the present example, a value indicating that a junction temperature of power supply circuit 20 is normal is written.

Power delivery control unit 16 reads information from register 26 (sequence sq27). Information is read in response to an instruction from power delivery control unit 16 to power delivery power supply unit 14 every prescribed period.

Power delivery control unit 16 obtains information from register 26 , confirms that a temperature is normal, and gives a voltage instruction to power delivery power supply unit 14 (sequence sq28).

Power delivery power supply unit 14 changes a voltage upon receiving the voltage instruction (sequence sq29). Control circuit 24 of power delivery power supply unit 14 has register 26 store information on a voltage to be supplied in voltage setting region 26 A. Specifically, control circuit 24 sets an initial value as information on a voltage to be supplied in voltage setting region 26 A of register 26 . In the present example, 5 V is set.

<b4. Case of Abnormal Voltage>

FIG. 7 is a sequence diagram for illustrating an operation in power supply control system 1 based on the first embodiment when a voltage is abnormal.

Referring to FIG. 7 , it is assumed that a voltage is abnormal in power delivery power supply unit 14 (sequence sq30). Specifically, voltage abnormal condition determination circuit 22 B outputs a control signal (at the “H” level) to control circuit 24 when a voltage from voltage detection circuit 132 exceeds a reference value. Control circuit 24 carries out power supply off control of power supply circuit 20 and has power supply circuit 20 stop an operation for power supply. Specifically, 0 V is set.

Then, in power delivery power supply unit 14 , information is written in register 26 (sequence sq31). Specifically, control circuit 24 writes information on an abnormal voltage in status storage region 26 B of register 26 .

Power delivery control unit 16 reads information from register 26 (sequence sq32). Information is read in response to an instruction from power delivery control unit 16 to power delivery power supply unit 14 every prescribed period.

Power delivery control unit 16 obtains information from register 26 , confirms that a voltage is abnormal, and gives a hard reset notification (sequence sq33). Power delivery control unit 16 gives a hard reset notification to power delivery control unit 104 .

Power reception device 100 which is the consumption side accepts the hard reset notification (sequence sq34). Power reception device 100 is thus set to the stand-by state in which voltage supply from power feed device 10 is awaited.

Then, power delivery control unit 16 gives a voltage instruction to power delivery power supply unit 14 (sequence sq35).

Power delivery power supply unit 14 changes a voltage upon receiving the voltage instruction (sequence sq36). Control circuit 24 of power delivery power supply unit 14 has register 26 store information on a voltage to be supplied in voltage setting region 26 A. Specifically, control circuit 24 sets an initial value as information on a voltage to be supplied in voltage setting region 26 A of register 26 . In the present example, 5 V is set.

Power delivery power supply unit 14 writes information in register 26 (sequence sq37). Specifically, control circuit 24 resets information indicating an abnormal voltage stored in status storage region 26 B of register 26 .

Therefore, in the case of an abnormal voltage, when an abnormal condition is sensed, an operation for power supply by power supply circuit 20 is stopped, however, the abnormal condition may be temporary. Therefore, an operation for stopping an operation for power supply and thereafter resuming an operation for supply of a voltage is repeated.

<C. Control Flow>

<c1. Regulation of Voltage Level>

FIG. 8 is a flowchart when processing for regulating a voltage level in power delivery control unit 16 based on the first embodiment is performed.

Referring to FIG. 8 , power delivery control unit 16 determines whether or not a voltage request has been issued from power reception device 100 which is the consumption side (step S 2 ).

When a voltage request has not been issued from power reception device 100 which is the consumption side in step S 2 (NO in step S 2 ), power delivery control unit 16 does not have to regulate a voltage level and a state in step S 2 is maintained.

When a voltage request has been issued from power reception device 100 which is the consumption side in step S 2 (YES in step S 2 ), power delivery control unit 16 checks a voltage request for power feed (step S 4 ).

Then, power delivery control unit 16 determines whether or not a voltage request is OK (step S 6 ). Specifically, power delivery control unit 16 determines whether or not power can be fed in response to the voltage request from power reception device 100 . Whether or not a value of a requested voltage level is within a power feed allowable range is checked.

Then, when power delivery control unit 16 determines that a voltage request is OK (YES in step S 6 ), it gives a notification that a voltage is permitted (step S 8 ). Power delivery control unit 16 notifies power delivery control unit 104 of power reception device 100 which is the consumption side that the voltage is permitted. Power reception device 100 is thus set to the stand-by state and waits for an instruction indicating being ready from the power feed side.

Then, power delivery control unit 16 determines whether or not it has received a notification that permission is accepted (step S 9 ).

Power delivery control unit 16 maintains step S 9 until it receives a notification that permission is accepted, and when it determines that it has received such a notification (YES in step S 9 ), it gives a voltage instruction to power delivery power supply unit 14 (step S 10 ). Power delivery power supply unit 14 changes a voltage upon receiving the voltage instruction.

Then, power delivery control unit 16 determines whether or not a prescribed period has elapsed (step S 12 ). The prescribed period is set in advance to a period equal to or longer than a period necessary until change to a new voltage is made from issuance of the voltage instruction to power delivery power supply unit 14 .

When power delivery control unit 16 determines that the prescribed period has elapsed (YES in step S 12 ), it notifies power reception device 100 which is the consumption side that the voltage is ready (step S 14 ). Then, the process ends (end).

Thus, power reception device 100 accepts the voltage being ready, makes transition from the stand-by state to a current consumption state, and is driven upon receiving supply of a voltage from power feed device 10 .

When power delivery control unit 16 determines in step S 6 that a voltage request is not OK (NO in step S 6 ), it gives a notification that a voltage is not permitted (not permitted) (step S 16 ).

Then, the process ends (end). In this case, requested power supply to power reception device 100 is not started.

<c2. Operation for Regulating Voltage of Power Delivery Power Supply Unit 14 >

FIG. 9 is a flowchart illustrating an operation for regulating a voltage in power delivery power supply unit 14 based on the first embodiment. An operation of control circuit 24 of power delivery power supply unit 14 will be described.

Referring to FIG. 9 , control circuit 24 determines whether or not a voltage instruction has been received from power delivery control unit 16 (step S 30 ).

In step S 30 , control circuit 24 maintains a state until a voltage instruction is received from power delivery control unit 16 , and when it receives the voltage instruction (YES in step S 30 ), it has register 26 store information (step S 32 ). Specifically, information is stored in voltage setting region 26 A of register 26 .

Then, control circuit 24 instructs power supply circuit 20 to output an indicated voltage (step S 34 ). Power supply circuit 20 regulates a level of a power supply voltage generated in accordance with the instruction from control circuit 24 until a target voltage is attained.

Then, the process ends (end).

<c3. Operation of Power Delivery Power Supply Unit 14 when Temperature is Abnormal>

FIG. 10 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the first embodiment when a temperature is abnormal. An operation of control circuit 24 of power delivery power supply unit 14 will be described.

Referring to FIG. 10 , control circuit 24 determines whether or not a temperature is abnormal (step S 40 ). Control circuit 24 determines whether or not a control signal (at the “H” level) is input from temperature abnormal condition determination circuit 22 A.

In step S 40 , control circuit 24 maintains a state until it determines that a temperature is abnormal, and when it determines that a temperature is abnormal (YES in step S 40 ), it stops an operation (step S 42 ). Control circuit 24 carries out power supply off control and instructs power supply circuit 20 to stop an operation for power supply. Specifically, 0 V is set.

Then, control circuit 24 has register 26 store information (step S 44 ). Specifically, control circuit 24 has information stored in status storage region 26 B of register 26 . Specifically, information indicating that a temperature is abnormal is stored.

Then, control circuit 24 determines whether or not a temperature is normal (step S 46 ). Control circuit 24 determines whether or not a control signal (at the “L” level) is input from temperature abnormal condition determination circuit 22 A.

In step S 46 , control circuit 24 maintains a state until it determines that a temperature is normal, and when it determines that a temperature is normal (YES in step S 46 ), it has register 26 store information (step S 48 ). Specifically, information is stored in status storage region 26 B of register 26 . Specifically, information indicating that a temperature is normal is stored.

Then, the process returns to step S 40 .

<c4. Recovery Operation when Temperature is Abnormal>

FIG. 11 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the first embodiment when a temperature is abnormal. An operation in microcomputer 34 of power delivery control unit 16 will mainly be described.

Referring to FIG. 11 , power delivery control unit 16 determines whether or not a prescribed period has elapsed (step S 50 ). In the present example, power delivery control unit 16 checks information in register 26 every prescribed period.

When power delivery control unit 16 determines that a prescribed period has elapsed (YES in step S 50 ), it checks register 26 (step S 52 ). Specifically, microcomputer 34 requests information in register 26 , and checks information stored in status storage region 26 B of register information transmitted from power delivery power supply unit 14 in response to the request.

Then, power delivery control unit 16 determines whether or not a temperature is abnormal as information in register 26 (step S 54 ). Specifically, microcomputer 34 determines whether or not there is information that a temperature is abnormal in status storage region 26 B of register 26 .

Then, when power delivery control unit 16 determines in step S 54 that a temperature is abnormal (YES in step S 54 ), it has stop of recovery continued (step S 56 ). In this case, microcomputer 34 does not give a voltage instruction to power delivery power supply unit 14 .

Then, the process returns to step S 50 and whether or not a prescribed period has elapsed is determined (step S 50 ).

When power delivery control unit 16 determines in step S 54 that a temperature is normal (NO in step S 54 ), it indicates recovery (step S 58 ). In this case, microcomputer 34 gives a voltage instruction to power delivery power supply unit 14 . Power delivery power supply unit 14 changes a voltage in response to the voltage instruction and performs a recovery operation.

Then, the process ends (end).

Therefore, when a temperature has reliably become low, a recovery operation can be performed based on information for determining whether or not a temperature is normal stored in register 26 .

Therefore, an operation appropriate in accordance with an abnormal condition can be performed on power supply circuit 20 based on information stored in status storage region 26 B of register 26 . Safety of power supply circuit 20 can thus be enhanced.

<c5. Operation of Power Delivery Power Supply Unit 14 when Voltage is Abnormal>

FIG. 12 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the first embodiment when a voltage is abnormal. An operation of control circuit 24 of power delivery power supply unit 14 will be described.

Referring to FIG. 12 , control circuit 24 determines whether or not a voltage is abnormal (step S 60 ). Control circuit 24 determines whether or not a control signal (at the “H” level”) is input from voltage abnormal condition determination circuit 22 B.

In step S 60 , control circuit 24 maintains a state until it determines that a voltage is abnormal, and when it determines that a voltage is abnormal (YES in step S 60 ), it stops an operation (step S 62 ). Control circuit 24 carries out power supply off control and instructs power supply circuit 20 to stop an operation for power supply by power supply circuit 20 . Specifically, 0 V is set.

Then, control circuit 24 has register 26 store information (step S 64 ). Specifically, control circuit 24 has information stored in status storage region 26 B of register 26 . Specifically, information indicating that a voltage is abnormal is stored.

Then, the process returns to step S 60 .

<c6. Recovery Operation when Voltage is Abnormal>

FIG. 13 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the first embodiment when a voltage is abnormal. An operation in microcomputer 34 of power delivery control unit 16 will mainly be described.

Referring to FIG. 13 , power delivery control unit 16 determines whether or not a prescribed period has elapsed (step S 70 ). In the present example, power delivery control unit 16 checks information in register 26 every prescribed period.

When power delivery control unit 16 determines that the prescribed period has elapsed (YES in step S 70 ), it checks register 26 (step S 72 ). Specifically, microcomputer 34 requests information in register 26 and checks information stored in status storage region 26 B of register information transmitted from power delivery power supply unit 14 in response to the request.

Then, power delivery control unit 16 determines whether or not a voltage is abnormal as information in register 26 (step S 74 ). Specifically, microcomputer 34 determines whether or not there is information that a voltage is abnormal in status storage region 26 B of register 26 .

When power delivery control unit 16 determines in step S 74 that a voltage is normal (NO in step S 74 ), the process returns to step S 70 .

When power delivery control unit 16 determines in step S 74 that a voltage is abnormal (YES in step S 74 ), it checks the number of times of recovery due to an abnormal voltage (step S 76 ). The number of times of recovery due to the abnormal voltage is stored in memory 36 of power delivery control unit 16 . Microcomputer 34 obtains the number of times of recovery due to the abnormal voltage stored in memory 36 .

Then, power delivery control unit 16 determines whether or not the number of times of recovery due to the abnormal voltage is equal to or more than a prescribed number of times (step S 78 ). Microcomputer 34 determines whether or not the number of times of recovery due to the abnormal voltage stored in memory 36 is equal to or more than the prescribed number of times.

When it is determined in step S 78 that the number of times of recovery due to the abnormal voltage is less than the prescribed number of times (NO in step S 78 ), recovery is indicated and register 26 is reset (step S 80 ). Specifically, microcomputer 34 gives a voltage instruction to power delivery power supply unit 14 . Power delivery power supply unit 14 changes a voltage in response to the voltage instruction and performs a recovery operation. An instruction to reset information on the abnormal voltage is given to power delivery power supply unit 14 . Thus, information indicating the abnormal voltage stored in status storage region 26 B of register 26 of power delivery power supply unit 14 is reset.

Then, power delivery control unit 16 counts up the number of times of recovery due to the abnormal voltage (step S 82 ). Microcomputer 34 of power delivery control unit 16 stores a value resulting from count-up as the number of times of recovery due to the abnormal voltage in memory 36 .

Then, the process returns to step S 70 .

When it is determined in step S 78 that the number of times of recovery due to the abnormal voltage is equal to or more than the prescribed number of times (YES in step S 78 ), recovery is stopped (step S 84 ).

Then, the process ends (end). Specifically, microcomputer 34 quits the process without giving a voltage instruction to power delivery power supply unit 14 . Therefore, in this case, a recovery operation is not performed.

In the present example, when the number of times of recovery is less than a prescribed number of times, an abnormal voltage may merely be sporadic and hence a recovery operation is performed. When the number of times of recovery is equal to or more than the prescribed number of times, an abnormal voltage is not merely sporadic but there may be another reason for a failure (such as short-circuiting) and hence a recovery operation is not performed.

Therefore, an operation appropriate in accordance with an abnormal condition can be performed on power supply circuit 20 based on information stored in status storage region 26 B of register 26 . Thus, safety of power supply circuit 20 can be enhanced.

<Modification>

<b5. Another Example when Temperature is Abnormal>

FIG. 14 is a sequence diagram for illustrating an operation in power supply control system 1 based on a modification of the first embodiment when a temperature is abnormal. In the present modification, a notification signal is output from power delivery power supply unit 14 to power delivery control unit 16 .

Referring to FIG. 14 , it is assumed that a temperature is abnormal in power delivery power supply unit 14 (sequence sq40). Specifically, temperature abnormal condition determination circuit 22 A outputs a control signal (at the “H” level) to control circuit 24 in accordance with a junction temperature of power supply circuit 20 .

Control circuit 24 carries out power supply off control of power supply circuit 20 and stops an operation for power supply by power supply circuit 20 . Specifically, 0 V is set.

Then, in power delivery power supply unit 14 , information is written in a register (sequence sq41). Specifically, control circuit 24 writes information on an abnormal temperature in status storage region 26 B of register 26 .

Then, power delivery power supply unit 14 performs processing for giving a notification to power delivery control unit 16 . Specifically, control circuit 24 outputs an interrupt notification signal to power delivery control unit 16 (sequence sq42).

Then, upon receiving the interrupt notification signal, power delivery control unit 16 reads information from register 26 (sequence sq43). Power delivery control unit 16 issues a request to power delivery power supply unit 14 for information in register 26 in response to the interrupt notification signal.

Power delivery control unit 16 obtains information from register 26 , confirms that a temperature is abnormal, and gives a hard reset notification (sequence sq44). Power delivery control unit 16 gives a hard reset notification to power delivery control unit 104 .

Power reception device 100 which is the consumption side accepts the hard reset notification (sequence sq45). Power reception device 100 is thus set to the stand-by state in which supply of a voltage from power feed device 10 is awaited.

Then, it is assumed that a temperature has returned to a normal condition in power delivery power supply unit 14 (sequence sq46).

Then, in power delivery power supply unit 14 , information is written in register 26 (sequence sq47). Specifically, control circuit 24 writes information on a temperature into status storage region 26 B of register 26 . In the present example, a value indicating that a junction temperature of power supply circuit 20 is normal is written.

Then, power delivery power supply unit 14 performs processing for giving a notification to power delivery control unit 16 . Specifically, control circuit 24 outputs an interrupt notification signal to power delivery control unit 16 (sequence sq48).

Upon receiving the interrupt notification signal, power delivery control unit 16 reads information from register 26 (sequence sq49). Power delivery control unit 16 requests information in register 26 of power delivery power supply unit 14 in response to the interrupt notification signal.

Power delivery control unit 16 obtains information from register 26 , confirms that a temperature is normal, and gives a voltage instruction to power delivery power supply unit 14 (sequence sq50).

Upon receiving the voltage instruction, power delivery power supply unit 14 changes a voltage (sequence sq51). Control circuit 24 of power delivery power supply unit 14 has register 26 store information on a voltage to be supplied in voltage setting region 26 A. Specifically, control circuit 24 sets an initial value as information on a voltage to be supplied in voltage setting region 26 A of register 26 . In the present example, 5 V is set.

In the present modification, an interrupt notification signal which notifies power delivery control unit 16 of the fact that writing in register 26 has been performed is output in writing in register 26 of power delivery power supply unit 14 . Thus, it is not necessary to obtain information in register 26 every prescribed period but information in register 26 should only be obtained in response to input of the interrupt notification signal. Therefore, load in monitoring of information in register 26 in power delivery control unit 16 is mitigated.

<c7. Another Operation of Power Delivery Power Supply Unit 14 when Temperature is Abnormal>

FIG. 15 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the modification of the first embodiment when a temperature is abnormal. An operation of control circuit 24 of power delivery power supply unit 14 will be described.

FIG. 15 is different from the flowchart in FIG. 10 in addition of steps S 45 and S 49 .

After information is stored in register 26 in step S 44 , power delivery power supply unit 14 issues an interrupt signal to power delivery control unit 16 (step S 45 ). Specifically, control circuit 24 outputs an interrupt notification signal to power delivery control unit 16 .

After information is stored in register 26 in step S 48 , power delivery power supply unit 14 issues an interrupt signal to power delivery control unit 16 (step S 49 ). Specifically, control circuit 24 outputs an interrupt notification signal to power delivery control unit 16 .

Then, the process returns to step S 40 . Since other portions are the same as in the flowchart in FIG. 10 , detailed description thereof will not be repeated.

<c8. Another Recovery Operation when Temperature is Abnormal>

FIG. 16 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the modification of the first embodiment when a temperature is abnormal. An operation in microcomputer 34 of power delivery control unit 16 will mainly be described.

FIG. 16 is different from the flowchart in FIG. 11 in replacement of step S 50 with step S 51 .

Specifically, power delivery control unit 16 determines whether or not an interrupt notification signal has been issued (step S 51 ). In the present example, microcomputer 34 of power delivery control unit 16 determines whether or not an interrupt notification signal has been received from power delivery power supply unit 14 .

Power delivery control unit 16 maintains a state in step S 51 until an interrupt notification signal is issued, and when it determines that the interrupt notification signal has been issued (YES in step S 51 ), it checks register 26 (step S 52 ). Specifically, microcomputer 34 requests information in register 26 and checks information stored in status storage region 26 B of register information transmitted from power delivery power supply unit 14 in response to the request.

Since other portions are the same as in the flowchart in FIG. 11 , detailed description thereof will not be repeated.

Though issuance of an interrupt signal when a temperature is abnormal has been described above, it can also similarly be applicable to an abnormal voltage.

<c9. Another Operation of Power Delivery Power Supply Unit 14 when Voltage is Abnormal>

FIG. 17 is a flowchart illustrating an operation of power delivery power supply unit 14 based on the modification of the first embodiment when a voltage is abnormal. An operation of control circuit 24 of power delivery power supply unit 14 will be described.

FIG. 17 is different from the flowchart in FIG. 12 in addition of step S 65 .

After information is stored in register 26 in step S 64 , control circuit 24 issues an interrupt signal to power delivery control unit 16 (step S 65 ). Specifically, control circuit 24 outputs an interrupt notification signal to power delivery control unit 16 .

Then, the process returns to step S 60 . Since other portions are the same as in the flowchart in FIG. 12 , detailed description thereof will not be repeated.

<c10. Another Recovery Operation when Voltage is Abnormal>

FIG. 18 is a flowchart illustrating a recovery operation of power delivery control unit 16 based on the modification of the first embodiment when a voltage is abnormal. An operation in microcomputer 34 of power delivery control unit 16 will mainly be described.

FIG. 18 is different from the flowchart in FIG. 13 in replacement of step S 70 with step S 71 .

Specifically, power delivery control unit 16 determines whether or not an interrupt notification signal has been issued (step S 71 ). In the present example, microcomputer 34 of power delivery control unit 16 determines whether or not an interrupt notification signal has been received from power delivery power supply unit 14 .

Power delivery control unit 16 maintains a state in step S 71 until an interrupt notification signal is issued, and when it determines that the interrupt notification signal has been issued (YES in step S 71 ), it checks register 26 (step S 72 ). Specifically, microcomputer 34 requests information in register 26 and checks information stored in status storage region 26 B of register information transmitted from power delivery power supply unit 14 in response to the request.

Since other portions are the same as in the flowchart in FIG. 13 , detailed description thereof will not be repeated.

In the present modification, an interrupt notification signal which notifies power delivery control unit 16 that writing in register 26 has been performed is output in writing in register 26 of power delivery power supply unit 14 . Thus, it is not necessary to obtain information in register 26 every prescribed period but information in register 26 should only be obtained in response to input of the interrupt notification signal. Therefore, load in monitoring of information in register 26 in power delivery control unit 16 is mitigated.

<Other Forms>

Though a configuration in power reception device 100 in which supply of a power supply voltage is received from power feed device 10 has been described, power reception device 100 can also include power delivery power supply unit 14 as in power feed device 10 . Power reception device 100 can also have a function as power feed device 10 and can also be configured to supply a power supply voltage to yet another USB device.

Second Embodiment

A scheme capable of ensuring safety of power feed at a high voltage will now be described.

<a4. Configuration of Power Supply Control System 1 #>

FIG. 19 is a diagram illustrating a configuration of power supply control system 1 # based on a second embodiment.

Referring to FIG. 19 , a power supply control system 1 # includes a power feed device (power feed control device) 10 # and power reception device 100 .

Replacement of power feed device 10 with power feed device 10 # is different from the configuration in FIG. 1 . Since the configuration is otherwise similar, detailed description thereof will not be repeated.

Power feed device 10 # is different from power feed device 10 in that power delivery power supply unit 14 is replaced with a power delivery power supply unit 14 # and power delivery control unit 16 is replaced with a power delivery control unit 16 #. Since the configuration is otherwise the same as described with reference to FIG. 1 , detailed description thereof will not be repeated.

<a5. Configuration of Power Feed Device 10 #>

FIG. 20 is a diagram illustrating a configuration of power feed device 10 # based on the second embodiment.

Referring to FIG. 20 , power feed device 10 # includes USB connector 12 , power delivery power supply unit 14 #, and power delivery control unit 16 #. USB data control unit 18 is omitted.

Power delivery power supply unit 14 # includes power supply circuit 20 , a voltage determination circuit 23 , control circuit 24 , a timer 25 , a register 27 , and interface 28 .

Power delivery power supply unit 14 # is different from power delivery power supply unit 14 in that voltage determination circuit 23 is provided instead of protection circuit 22 , register 27 is provided instead of register 26 , and timer 25 is further provided. Since the configuration is otherwise similar, detailed description thereof will not be repeated.

Voltage determination circuit 23 determines whether or not a value of a voltage regulated by power supply circuit 20 has attained to a set voltage. Voltage determination circuit 23 outputs a result of determination to control circuit 24 . When control circuit 24 determines that a value of the voltage regulated by power supply circuit 20 has attained to the set voltage based on a result of determination by voltage determination circuit 23 , it outputs a notification signal to external power delivery control unit 16 #.

Control circuit 24 controls entire power delivery power supply unit 14 #.

Register 27 stores information on power delivery power supply unit 14 #.

Specifically, register 27 stores information on setting of a power supply voltage of power supply circuit 20 .

Control circuit 24 writes data in register 27 as necessary.

Timer 25 has a time counting function and counts time in response to an instruction from control circuit 24 .

Power delivery control unit 16 # includes interface 30 , communication interface 32 , microcomputer 34 , a timer 35 , and memory 36 .

Power delivery control unit 16 # is different from power delivery control unit 16 in further including timer 35 . Since the configuration is otherwise the same as in power delivery control unit 16 , detailed description thereof will not be repeated.

Timer 35 has a time counting function and counts time in response to an instruction from microcomputer 34 .

<a6. Configuration of Voltage Determination Circuit 23 >

FIG. 21 is a diagram illustrating a configuration of voltage determination circuit 23 based on the second embodiment.

Referring to FIG. 21 , voltage determination circuit 23 includes a determination unit 200 .

Specifically, determination unit 200 compares an output voltage regulated by power supply circuit 20 with a reference value, and determines whether or not the output voltage regulated by power supply circuit 20 has attained to (reached) the reference value. The reference value is calculated based on information on setting of the power supply voltage of power supply circuit 20 stored in register 27 .

Whether or not the output voltage regulated by power supply circuit 20 has attained to (reached) the reference value includes not only an example where the voltage is the same as the reference value but also an example where the voltage is in the vicinity of the reference value. Specifically, it is determined that the reference value has been reached when a difference between a voltage value and the reference value is within a prescribed range.

Determination unit 200 compares an output voltage regulated by power supply circuit 20 with the reference value, and when it determines that the output voltage regulated by power supply circuit 20 has attained to (reached) the reference value, it outputs that determination to control circuit 24 .

Control circuit 24 outputs a notification signal to power delivery control unit 16 # based on a result of determination by determination unit 200 .

Power delivery control unit 16 # notifies power delivery control unit 104 that the voltage is ready. Power reception device 100 starts consumption of a current upon receiving the notification.

<b5. Regulation of Voltage Level>

FIG. 22 is a sequence diagram when a voltage level is regulated from an old voltage to a new voltage in power supply control system 1 # based on the second embodiment.

Referring to FIG. 22 , power reception device 100 which is the consumption side issues a voltage request (sequence sq1). Power delivery control unit 104 issues a request to power delivery control unit 16 # for a voltage necessary for power reception device 100 .

Power delivery control unit 16 # determines whether or not power can be fed in response to the voltage request from power reception device 100 . The power delivery control unit checks whether or not a value of a requested voltage level is within a power feed allowable range. When it is determined that the value of the requested voltage level is within the power feed allowable range, a notification that the voltage is permitted is given to power delivery control unit 104 (sequence sq2).

Power reception device 100 which is the consumption side accepts permission (sequence sq3).

Power reception device 100 is thus set to the stand-by state and waits for an instruction indicating being ready from the power feed side.

Power delivery control unit 104 outputs a notification that permission is accepted to power feed device 10 # upon receiving the notification that the voltage is permitted from power feed device 10 # which is the supply side.

Upon receiving the notification, power feed device 10 # starts an operation to regulate a voltage on the side of power feed device 10 # (sequence sq61).

Power delivery control unit 16 # transmits voltage information to power delivery power supply unit 14 # through interface 30 and interface 28 . Control circuit 24 of power delivery power supply unit 14 # has register 27 store information on a voltage to be supplied (sequence sq62).

Control circuit 24 of power delivery power supply unit 14 # instructs power supply circuit 20 to output a voltage based on information on the voltage set in register 27 . Thus, the output voltage is changed from the old voltage to a new voltage (sequence sq63).

Then, when voltage determination circuit 23 determines that the indicated voltage has attained to (reached) the reference value in power supply circuit 20 , it outputs that determination to control circuit 24 . When control circuit 24 determines that the indicated voltage has attained to (reached) the reference value in power supply circuit 20 , it gives a notification signal to power delivery control unit 16 # (sequence sq64).

Power delivery control unit 16 # determines whether or not a notification signal from power delivery power supply unit 14 # has been received after lapse of a prescribed period since transmission of voltage information to power delivery power supply unit 14 #, and when the notification signal has been received, it notifies power reception device 100 which is the consumption side that the voltage is ready (sequence sq65). The prescribed period is set in advance to a period equal to or longer than a period necessary until change to a new voltage is made from transmission of voltage information to power delivery power supply unit 14 #.

Power reception device 100 which is the consumption side accepts the voltage being ready upon receiving the notification that the voltage is ready from power feed device 10 # (sequence sq66).

Thus, power reception device 100 is set from the stand-by state to the current consumption state and driven upon receiving supply of a voltage from power feed device 10 #.

In the present scheme, power delivery control unit 16 # determines whether or not it has received a notification signal from power delivery power supply unit 14 # after lapse of a prescribed period since transmission of voltage information to power delivery power supply unit 14 #, and when it has received the notification signal, it notifies power reception device 100 which is the consumption side that a voltage is ready. Therefore, since power is fed after change to a new voltage has been confirmed, safety of power feed by the power feed device can be enhanced.

FIGS. 23A and 23B are diagrams illustrating an operation for changing a voltage in power supply circuit 20 based on the second embodiment.

As shown in FIG. 23A , in response to an instruction to change a voltage at time T 1 , a voltage increases from an initial voltage and is regulated in the vicinity of a set voltage.

At time T 2 , when a difference between the voltage regulated by power supply circuit 20 and a target set voltage is within a prescribed range, a notification signal is output.

At time T 3 , timing of lapse of a prescribed period since issuance of the instruction to change a voltage is shown. Power delivery control unit 16 # determines whether or not it has received a notification signal from power delivery power supply unit 14 # after lapse of a prescribed period since transmission of voltage information to power delivery power supply unit 14 #, and when it has received the notification signal, it notifies power reception device 100 which is the consumption side that a voltage is ready.

As shown in FIG. 23B , in accordance with an instruction to change a voltage at time T 4 , a voltage lowers from an initial voltage and is regulated in the vicinity of a set voltage.

At time T 5 , when a difference between the voltage regulated by power supply circuit 20 and the target set voltage is within a prescribed range, a notification signal is output.

At time T 6 , timing of lapse of a prescribed period since issuance of the instruction to change a voltage is shown. Power delivery control unit 16 # determines whether or not it has received a notification signal from power delivery power supply unit 14 # after lapse of a prescribed period since transmission of voltage information to power delivery power supply unit 14 #, and when it has received the notification signal, it notifies power reception device 100 which is the consumption side that a voltage is ready.

<b6. In Case of Abnormal Condition in Regulation of Voltage Level>

FIG. 24 is a sequence diagram illustrating an operation in an abnormal condition in regulation of a voltage level in power supply control system 1 # based on the second embodiment.

Referring to FIG. 24 , sequences sq1 to sq3 and sq61 to sq63 are the same as the operations described with reference to FIG. 22 .

Control circuit 24 of power delivery power supply unit 14 # instructs power supply circuit 20 to output a voltage based on information on a voltage set in register 27 . Thus, in sequence sq63, an output voltage is changed from the old voltage to a new voltage.

In the present example, occurrence of an abnormal condition in power supply circuit 20 will be described.

Voltage determination circuit 23 does not output to control circuit 24 an indication that an indicated voltage has attained to (reached) the reference value in power supply circuit 20 . Therefore, control circuit 24 does not give a notification signal to power delivery control unit 16 #.

Power delivery control unit 16 # determines whether or not a notification signal has been received from power delivery power supply unit 14 # after lapse of a prescribed period since transmission of voltage information to power delivery power supply unit 14 #. When power delivery control unit 16 # determines that it has not received a notification signal after lapse of a prescribed period from power delivery power supply unit 14 #, it gives a hard reset notification to power delivery control unit 104 (sequence sq70).

Power reception device 100 which is the consumption side accepts the hard reset notification (sequence sq71). Thus, power reception device 100 is set to the stand-by state in which supply of a voltage from power feed device 10 # is awaited.

Then, power feed device 10 # which is the power feed side gives a reset instruction (sequence sq72). Power delivery control unit 16 # instructs power delivery power supply unit 14 # to reset.

Power delivery power supply unit 14 # changes a voltage upon receiving the reset instruction from power delivery control unit 16 # (sequence sq73). Control circuit 24 of power delivery power supply unit 14 # sets a voltage from power supply circuit 20 to 0 V upon receiving the reset instruction.

In the present scheme, power delivery control unit 16 # determines whether or not it has received a notification signal from power delivery power supply unit 14 # after lapse of a prescribed period since transmission of voltage information to power delivery power supply unit 14 #, and when it has not received the notification signal, it gives a reset instruction so as to cut off supply of a voltage. Therefore, when a voltage is abnormal, safety of power feed by the power feed device can be enhanced by cutting off a voltage.

<c11. Regulation of Voltage Level>

FIG. 25 is a flowchart when processing for regulating a voltage level in power delivery control unit 16 # based on the second embodiment is performed.

Referring to FIG. 25 , power delivery control unit 16 # determines whether or not a voltage request from power reception device 100 which is the consumption side has been issued (step S 2 ).

When there is no voltage request from power reception device 100 which is the consumption side in step S 2 (NO in step S 2 ), power delivery control unit 16 # does not have to regulate a voltage level and maintains a state in step S 2 .

When a voltage request from power reception device 100 which is the consumption side has been issued in step S 2 (YES in step S 2 ), power delivery control unit 16 # checks a voltage request in power feed (step S 4 ).

Then, power delivery control unit 16 # determines whether or not the voltage request is OK (step S 6 ). Specifically, power delivery control unit 16 # determines whether or not power can be fed in response to the voltage request from power reception device 100 . Whether or not a value of a requested voltage level is within a power feed allowable range is checked.

When power delivery control unit 16 # determines that the voltage request is OK (YES in step S 6 ), it gives a notification that a voltage is permitted (step S 8 ). Power delivery control unit 16 # notifies power delivery control unit 104 of power reception device 100 which is the consumption side that a voltage is permitted. Power reception device 100 is thus set to the stand-by state and waits for an instruction indicating being ready from the power feed side.

Then, power delivery control unit 16 # determines whether or not it has received a notification that permission is accepted (step S 9 ).

Power delivery control unit 16 # maintains step S 9 until it receives a notification that permission is accepted, and when it determines that it has received the notification (YES in step S 9 ), it transmits voltage information to power delivery power supply unit 14 # (step S 10 #). Power delivery power supply unit 14 # changes a voltage upon receiving transmission of the voltage information (an instruction to change).

Then, power delivery control unit 16 # determines whether or not a prescribed period has elapsed (step S 12 ). The prescribed period is set in advance to a period equal to or longer than a period necessary until change to a new voltage is made from transmission of voltage information to power delivery power supply unit 14 #.

When power delivery control unit 16 # determines that a prescribed period has elapsed (YES in step S 12 ), it determines whether or not a notification signal has been issued from power delivery power supply unit 14 # (step S 13 ).

When power delivery control unit 16 # determines in step S 13 that the notification signal has been issued from power delivery power supply unit 14 # (YES in step S 13 ), it notifies power reception device 100 which is the consumption side that a voltage is ready (step S 14 ). Then, the process ends (end).

Power reception device 100 thus accepts the indication that the voltage is ready, makes transition from the stand-by state to the current consumption state, and is driven upon receiving supply of a voltage from power feed device 10 #.

When power delivery control unit 16 # determines in step S 6 that a voltage request is not OK (NO in step S 6 ), it gives a notification that a voltage is not permitted (not permitted) (step S 16 ).

Then, the process ends (end). In this case, requested power supply to power reception device 100 is not started.

When power delivery control unit 16 # determines in step S 13 that no notification signal has been issued from power delivery power supply unit 14 # (NO in step S 13 ), it gives a hard reset notification to power reception device 100 which is the consumption side (step S 17 ).

Then, power delivery control unit 16 # gives a reset instruction to power delivery power supply unit 14 # (step S 18 ). Power delivery power supply unit 14 # sets a voltage to 0 V upon receiving the reset instruction. Then, the process ends (end).

<c12. Operation for Regulating Voltage by Power Delivery Power Supply Unit 14 #>

FIG. 26 is a flowchart illustrating an operation for regulating a voltage of power delivery power supply unit 14 # based on the second embodiment. An operation of control circuit 24 of power delivery power supply unit 14 # will be described.

Referring to FIG. 26 , control circuit 24 determines whether or not a value in the register storing an output voltage has been changed in response to a voltage instruction from power delivery control unit 16 # (step S 130 ).

When a value in the register storing an output voltage has been changed in step S 130 in response to the voltage instruction from power delivery control unit 16 # (YES in step S 130 ), control circuit 24 instructs power supply circuit 20 to output a voltage value stored in register 27 (step S 131 ).

Then, the process ends (end).

<b7. Operation for Determining Abnormal Condition During Power Feed>

FIG. 27 is a sequence diagram illustrating a normal operation during power feed from power delivery power supply unit 14 # to power reception device 100 based on the second embodiment.

Referring to FIG. 27 , power delivery control unit 16 # which is the power feed side outputs a timer reset command for resetting timer 25 to power delivery power supply unit 14 # every prescribed period (sequences sq80, sq81, sq82, and sq83).

Power delivery power supply unit 14 # initializes a timer value and starts counting upon receiving the timer reset command from power delivery control unit 16 #. This processing is repeated each time of the timer reset command.

FIG. 28 is a sequence diagram illustrating an operation when an abnormal condition occurs during power feed from power delivery power supply unit 14 # to power reception device 100 based on the second embodiment.

Referring to FIG. 28 , power delivery control unit 16 # which is the power feed side outputs a timer reset command for resetting timer 25 to power delivery power supply unit 14 # every prescribed period (sequence sq90).

Power delivery power supply unit 14 # initializes a timer value and starts counting upon receiving the timer reset command from power delivery control unit 16 #.

In the present example, a timer value of timer 25 has exceeded a prescribed value (timer overflow).

When power delivery power supply unit 14 # determines that the timer value has exceeded the prescribed value, it instructs power delivery control unit 16 # to perform a reset operation (sequence sq91).

Power delivery control unit 16 # performs a prescribed initial launch operation in accordance with an instruction for a reset operation from power delivery power supply unit 14 # (sequence sq92). The initial launch operation is an operation for resetting entire power delivery control unit 16 # based on a prescribed reset program stored in memory 36 .

Power delivery control unit 16 # gives a hard reset notification to power feed device 10 # which is the power feed side together with the initial launch operation (sequence sq93). Power delivery control unit 16 # gives a hard reset notification to power delivery control unit 104 .

Power reception device 100 which is the consumption side accepts the hard reset notification (sequence sq94). Thus, power reception device 100 is set to the stand-by state in which supply of a voltage from power feed device 10 # is awaited.

In response, power feed device 10 # starts a voltage regulation operation on its side (sequence sq95).

Power delivery control unit 16 # transmits voltage information to power delivery power supply unit 14 # through interface 30 and interface 28 . Control circuit 24 of power delivery power supply unit 14 # has register 27 store information on a voltage to be supplied (sequence sq96). Specifically, control circuit 24 sets an initial value as information on a voltage to be supplied in register 27 . In the present example, 5 V is set.

Control circuit 24 of power delivery power supply unit 14 # instructs power supply circuit 20 to output a voltage based on information on a voltage set in register 27 . Thus, the output voltage is changed from the old voltage to a new voltage (sequence sq97).

In the present scheme, power delivery power supply unit 14 # instructs power delivery control unit 16 # to perform a reset operation when a prescribed condition is satisfied. Specifically, when there is no input of a timer reset command periodically input from power delivery control unit 16 #, power delivery power supply unit 14 # determines that there is some kind of abnormal condition in power delivery control unit 16 # and gives an instruction to perform a reset operation indicating execution of an initial launch operation. Thus, power delivery power supply unit 14 # can also monitor a state of power delivery control unit 16 #. Power delivery control unit 16 # can determine a state of power delivery power supply unit 14 # in accordance with a notification signal from voltage determination circuit 23 . Therefore, power delivery control unit 16 # and power delivery power supply unit 14 # monitor states of each other, and if there is an abnormal condition, they can perform a reset operation. Therefore, safety of power feed by the power feed device can be enhanced.

<c13. Operation for Timer Reset Command by Power Delivery Control Unit 16 #>

FIG. 29 is a flowchart illustrating an operation of power delivery control unit 16 # based on the second embodiment in issuance of a timer reset command. An operation of microcomputer 34 of power delivery control unit 16 # will be described.

Referring to FIG. 29 , microcomputer 34 determines whether or not a prescribed period has elapsed (step S 140 ). Microcomputer 34 may determine whether or not a prescribed period has elapsed with the use of timer 35 .

When microcomputer 34 determines in step S 140 that a prescribed period has elapsed (YES in step S 140 ), it outputs a timer reset command (step S 142 ).

Then, the process returns to step S 140 and the process is repeated.

<c14. Operation for Timer Reset Command by Power Delivery Power Supply Unit 14 #>

FIG. 30 is a flowchart illustrating an operation of power delivery power supply unit 14 # based on the second embodiment in issuance of a timer reset command. An operation of control circuit 24 of power delivery power supply unit 14 # will be described.

Referring to FIG. 30 , control circuit 24 determines whether or not a timer reset command has been input (step S 150 ).

When control circuit 24 determines in step S 150 that the timer reset command has been input (YES in step S 150 ), it resets timer 25 (step S 152 ).

Then, the process returns to step S 150 .

When control circuit 24 determines in step S 150 that there is no input of the timer reset command (NO in step S 150 ), control circuit 24 instructs to timer for counting (step S 154 ).

Then, whether or not a timer value of timer 25 has exceeded a prescribed value (timer over) is determined (step S 156 ).

When it is determined in step S 156 that a timer value of timer 25 has exceeded the prescribed value (YES in step S 156 ), a reset operation instruction is given (step S 158 ).

Then, the process ends (end).

When it is determined in step S 156 that a timer value of timer 25 has not exceeded the prescribed value (NO in step S 156 ), the process returns to step S 150 and the process is repeated.

Third Embodiment

FIG. 31 is a diagram illustrating a configuration of a power feed device 11 based on a third embodiment.

Referring to FIG. 31 , power feed device 11 has a plurality of USB connectors 12 A and 12 B. The USB data control unit is not shown.

A power delivery power supply unit 14 #A and a power delivery control unit 16 #A are included in correspondence with USB connector 12 A.

A power delivery power supply unit 14 #B and a power delivery control unit 16 #B are included in correspondence with USB connector 12 B.

Since power delivery power supply units 14 #A and 14 #B are basically similar in configuration to power delivery power supply unit 14 # in FIG. 20 , detailed description thereof will not be repeated. “A” and “B” are affixed to a reference numeral for each constituent element of power delivery power supply unit 14 # in FIG. 20 .

Since power delivery control units 16 #A and 16 #B are basically similar in configuration to power delivery control unit 16 # in FIG. 20 , detailed description thereof will not be repeated. “A” and “B” are affixed to a reference numeral for each constituent element of power delivery control unit 16 # in FIG. 20 .

A microcomputer 34 A and a microcomputer 34 B supply and receive data to and from each other.

<c15. Regulation of Voltage Level>

FIG. 32 is a flowchart when processing for regulating a voltage level in each of power delivery control units 16 #A and 16 #B based on the third embodiment is performed.

Referring to FIG. 32 , replacement of step S 4 in which a voltage request in power feed is checked with step S 4 # is different from the flowchart in FIG. 25 . Since other portions are the same as described with reference to FIG. 25 , detailed description thereof will not be repeated.

FIG. 33 is a flowchart illustrating a sub routine process for checking a voltage request in power feed in step S 4 #.

As shown in FIG. 33 , power delivery control units 16 #A and 16 #B determine whether or not another port is being used (step S 160 ). For example, power delivery control unit 16 #B determines whether or not a USB device is connected to USB connector 12 A which is another port different from USB connector 12 B which is a corresponding port. Microcomputer 34 B accesses microcomputer 34 A and checks whether or not a USB device is connected to USB connector 12 A.

When power delivery control units 16 #A and 16 #B determine in step S 160 that another port is being used (YES in step S 160 ), they obtain an amount of electric power used by another port (step S 162 ). For example, microcomputer 34 B of power delivery control unit 16 #B accesses microcomputer 34 A, and when it determines that a USB device is connected to USB connector 12 A, it obtains information on an amount of electric power used by that USB device.

Then, power delivery control units 16 #A and 16 #B calculate an amount of suppliable electric power (step S 164 ). Power delivery control unit 16 #B calculates an amount of suppliable electric power by subtracting an amount of electric power used from a maximum amount of suppliable electric power of power supply input AC or DC power supply input.

Then, power delivery control units 16 #A and 16 #B obtain a requested amount of electric power (step S 166 ). Power delivery control units 16 #A and 16 #B obtain requested amounts of electric power based on voltage requests from USB devices connected to corresponding USB connectors 12 A and 12 B, respectively.

Power delivery control units 16 #A and 16 #B determine whether or not the obtained requested amounts of electric power of the USB devices are within a range of an amount of suppliable electric power (step S 168 ).

When power delivery control units 16 #A and 16 #B determine in step S 168 that the requested amounts of electric power are within the range of the amount of suppliable electric power (YES in step S 168 ), they make a determination as request OK (step S 170 ).

Then, the process ends (return). The process proceeds to step S 6 .

When power delivery control units 16 #A and 16 #B determine in step S 168 that the requested amounts of electric power are not within the range of the amount of suppliable electric power (NO in step S 168 ), they give a request (step S 172 ). Specifically, power delivery control units 16 #A and 16 #B transmit to power reception device 100 , information that only electric power in the amount of suppliable electric power can be fed. Power reception device 100 determines whether or not to request power feed in that amount of electric power based on information that electric power only in the amount of suppliable electric power can be fed. Since power consumption can be reduced in drive of power reception device 100 in a power save mode, whether or not power can be fed by changing a mode is determined. If electric power can be fed, power reception device 100 outputs a notification of acceptance to power feed device 10 #.

Then, power delivery control units 16 #A and 16 #B determine whether or not a notification of acceptance has been given from power reception device 100 (step S 174 ). Microcomputers 34 A and 34 B of respective power delivery control units 16 #A and 16 #B determine whether or not they have received a notification of acceptance from power reception device 100 .

When power delivery control units 16 #A and 16 #B determine in step S 174 that they have received the notification of acceptance (YES in step S 174 ), they make a determination as request OK for an amount of suppliable electric power (step S 176 ). Microcomputers 34 A and 34 B of respective power delivery control units 16 #A and 16 #B make a determination as request OK for an amount of suppliable electric power. Then, the process ends (return). The process proceeds to step S 6 .

When power delivery control units 16 #A and 16 #B determine in step S 174 that they have not received a notification of acceptance (NO in step S 174 ), they make a determination as request NG (step S 178 ). In this case, electric power is not fed to power reception device 100 .

Then, the process ends (return). The process proceeds to step S 6 .

When power delivery control units 16 #A and 16 #B determine in step S 160 that another port is not being used (NO in step S 160 ), they obtain a requested amount of electric power (step S 180 ). Power delivery control units 16 #A and 16 #B obtain requested amounts of electric power based on voltage requests from USB devices connected to corresponding USB connectors 12 A and 12 B, respectively.

Power delivery control units 16 #A and 16 #B determine whether or not the requested amounts of electric power are within the range of the amount of suppliable electric power (step S 182 ).

When power delivery control units 16 #A and 16 #B make a determination in step S 182 that the requested amounts of electric power are within the range of the amount of suppliable electric power (YES in step S 182 ), they make a determination as request OK (step S 184 ).

Then, the process ends (return). The process proceeds to step S 6 .

When power delivery control units 16 #A and 16 #B make a determination in step S 182 that the requested amounts of electric power are not within the range of the amount of suppliable electric power (NO in step S 182 ), they make a determination as request NG (step S 186 ). Then, the process ends (return). The process proceeds to step S 6 .

In the present scheme, with a plurality of USB connectors 12 A and 12 B being provided, for example, when a USB device is attached to USB connector 12 A and thereafter a USB device is attached to USB connector 12 B, whether or not electric power can be fed to the USB device connected to USB connector 12 B is determined. Whether or not the requested amounts of electric power are within a range of an amount of suppliable electric power is determined, and when the requested amounts of electric power are not within the range of the suppliable electric power, an inquiry request as to whether or not feed with suppliable electric power to the USB device can be done is issued.

When the USB device outputs a notification of acceptance in response to the inquiry request, electric power in the amount of suppliable electric power is fed. Accordingly, a voltage is supplied from power delivery power supply unit 14 # based on the amount of suppliable electric power.

Thus, even when a total amount of electric power requested by the plurality of USB devices exceeds the maximum amount of suppliable electric power, whether or not electric power in an amount of suppliable electric power can be fed is checked by issuing a request. If electric power can be fed, electric power in an amount of suppliable electric power is fed. Thus, electric power can be fed from the power feed device to the plurality of USB devices with safety of power feed at a high voltage being ensured.

Fourth Embodiment

In the third embodiment, the process is performed by supplying and receiving data between power delivery control unit 16 #A and power delivery control unit 164 B. Without being limited to such a configuration, for example, power delivery control unit 16 #A and power delivery control unit 16 #B may both be managed.

FIG. 34 is a diagram illustrating a configuration of a power feed device 11 # based on a fourth embodiment.

Referring to FIG. 34 , power feed device 11 # includes a plurality of USB connectors 12 A and 12 B.

Power delivery power supply unit 14 #A and power delivery control unit 16 #A are included in correspondence with USB connector 12 A.

Power delivery power supply unit 14 #B and power delivery control unit 16 #B are included in correspondence with USB connector 12 B.

In the present example, a power delivery management unit 19 managing power delivery control units 16 #A and 16 #B is further provided.

Since each of power delivery power supply units 14 #A and 14 #B is basically similar in configuration to power delivery power supply unit 14 # in FIG. 20 , detailed description thereof will not be repeated. “A” and “B” are affixed to a reference numeral for each constituent element of power delivery power supply unit 14 # in FIG. 20 .

Since each of power delivery control units 16 #A and 16 #B is basically similar in configuration to power delivery control unit 16 # in FIG. 20 , detailed description thereof will not be repeated. “A” and “B” are affixed to a reference numeral for each constituent element of power delivery control unit 16 # in FIG. 20 .

Microcomputer 34 A and microcomputer 34 B supply and receive data to and from power delivery management unit 19 .

Power delivery management unit 19 may perform a part of processing in regulation of a voltage level described above.

Specifically, power delivery management unit 19 may perform processing for checking a voltage request in power feed described with reference to FIG. 33 .

When there is a voltage request from power reception device 100 which is the consumption side, power delivery control units 16 #A and 16 #B output an indication to that effect to power delivery management unit 19 .

Then, power delivery management unit 19 checks a voltage request in power feed.

Since the processing for checking a voltage request in power feed in power delivery management unit 19 is the same as in the flowchart described with reference to FIG. 15 , detailed description thereof will not be repeated.

Then, power delivery management unit 19 checks the voltage request in power feed. When power can be fed, the power delivery management unit makes a determination as request OK and provides the determination to power delivery control units 16 #A and 16 #B.

Since processing thereafter is the same as described with reference to FIG. 32 , detailed description thereof will not be repeated.

<Other Forms>

Though supply of a power supply voltage is received from power feed device 10 # in power reception device 100 , power reception device 100 can also include power delivery power supply unit 14 # and power delivery control unit 16 # similarly to power feed device 10 #. Power reception device 100 can also have a function as power feed device 10 # and supply a power supply voltage to yet another USB device.

Though the embodiments of the present invention have been described, it should be understood that the embodiments disclosed herein are illustrative and non-restrictive in every respect. The scope of the present invention is defined by the terms of the claims and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.