Switch control circuit and electronic device using the same

The subject matter herein generally relates to switch control circuits and an electronic device using the same.

In a server system, a baseboard management controller (BMC) communicates with a backplane chip via an inter-integrated circuit (I2C) bus. In generally, the backplane chip always transmits data to the BMC even though the BMC does not need to communicate with the backplane chip.

Implementations of the present technology will now be described, by way of example only, with reference to the attached figures.

FIG. 1 is a block diagram of an embodiment of an electronic device of the present disclosure, the electronic device including a switch control circuit.

FIG. 2 is a circuit diagram of an embodiment of the switch control circuit of FIG. 1 .

It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale and the proportions of certain parts may be exaggerated to better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.

Several definitions that apply throughout this disclosure will now be presented.

The term “coupled” is defined as connected, whether directly or indirectly through intervening components, and is not necessarily limited to physical connections. The connection can be such that the objects are permanently connected or releasably connected. The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series, and the like.

FIG. 1 illustrates an electronic device 400 of an embodiment of the present disclosure.

The electronic device 400 can comprise an switch control circuit 100 , a baseboard management controller (BMC) 200 , and a backplane chip 300 . The switch control circuit 100 is installed in the electronic device 400 . The switch control circuit 100 is electrically coupled between the BMC 200 and the backplane chip 300 to control communications between the BMC 200 and the backplane chip 300 . In at least one embodiment, the electronic device 400 can be a server.

FIG. 2 illustrates an embodiment of the switch control circuit 100 . The switch control circuit 100 can comprise a logic component 10 and a switch circuit 20 . The switch circuit 20 is electrically coupled between the BMC 200 and the backplane chip 300 . The logic component 10 is electrically coupled between the BMC 200 and the switch circuit 20 to obtain a logic control signal from the BMC 200 . The logic component 10 outputs a switch signal to the switch circuit 20 according to the logic control signal outputted by the BMC 200 , to switch on or switch off the switch circuit 20 .

In at least one embodiment, the logic component 10 can be a NOR gate.

A logic component first input terminal is electrically coupled to a BMC general purpose input/output terminal (GPIO 1 ). A logic component second input terminal is electrically coupled to another BMC general purpose input/output terminal (GPIO 2 ). A logic component ground terminal is grounded. A logic component power supply terminal is electrically coupled to a power supply 3.3V_AUX. A logic component output terminal is electrically coupled to the switch circuit 20 .

The switch circuit 20 comprises a first electronic switch Q 1 , a second electronic switch Q 2 , a capacitor C 1 , and first to sixth resistors R 1 -R 6 .

A first electronic switch first terminal is electrically coupled to BMC clock pin BMC_SCL. The first electronic switch first terminal is electrically coupled to the power supply 3.3V_AUX through the first resistor R 1 . A first electronic switch second terminal is electrically coupled to backplane chip clock pin BP_SCL. The first electronic switch second terminal is electrically coupled to the power supply 3.3V_AUX through the second resistor R 2 . A first electronic switch third terminal is electrically coupled to the logic component output terminal through third resistor R 3 . The first electronic switch third terminal is electrically coupled to ground through the third resistor R 3 and the capacitor C 1 .

A second electronic switch first terminal is electrically coupled to BMC data pin BMC_SDA. The second electronic switch first terminal is electrically coupled to the power supply 3.3V_AUX through the fourth resistor R 4 . A second electronic switch second terminal is electrically coupled to backplane chip data pin BP_SDA. The second electronic switch second terminal is electrically coupled to the power supply 3.3V_AUX through the fifth resistor R 5 . A second electronic switch third terminal is electrically coupled to the logic component output terminal through sixth resistor R 6 . The second electronic switch third terminal is electrically coupled to ground through the sixth resistor R 6 and the capacitor C 1 .

In at least one embodiment, the first electronic switch Q 1 can be a field effect transistor (FET). The first electronic switch first terminal can be a FET source. The first electronic switch second terminal can be a FET drain. The first electronic switch third terminal can be a FET gate.

In at least one embodiment, the second electronic switch Q 2 can also be an FET. The second electronic switch first terminal can be FET source. The second electronic switch second terminal can be FET drain. The second electronic switch third terminal can be FET gate.

In use, when the electronic device BMC 200 needs to communicate with the backplane chip 300 , both the BMC GPIO 1 and the BMC GPIO 2 output, to the logic component first input terminal and the logic component second input terminal, a logic control signal at the low-voltage level, such as logic 0. The logic component 10 outputs a switch signal at high-voltage level, such as logic 1, to turn on the first electronic switch Q 1 and the second electronic switch Q 2 . Normal communication between the BMC 200 and the backplane chip 300 is thus enabled.

When communication between the electronic device BMC 200 and the backplane chip 300 is not needed, one or both of the BMC GPIO 1 and the BMC GPIO 2 outputs a logic control signal at high-voltage level, such as logic 1, to the logic component first input terminal or the logic component second input terminal. The logic component 10 outputs a switch signal at low-voltage level, such as logic 0, to turn off the first electronic switch Q 1 and the second electronic switch Q 2 . Communication between the BMC 200 and the backplane chip 300 is thus disabled.

The embodiments shown and described above are only examples. Many details are often found in the art such as the other features of switching circuit in an electronic device. Therefore, many such details are neither shown nor described. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, especially in matters of shape, size, and arrangement of the parts within the principles of the present disclosure, up to and including the full extent established by the broad general meaning of the terms used in the claims. It will therefore be appreciated that the embodiments described above may be modified within the scope of the claims.