Switching circuit and control method of switching circuit

Abstract

The embodiment of the invention provides a switching circuit and a control method of the switching circuit. The switching circuit comprises a first power tube; and a driving circuit including: a first input terminal configured to receive a first voltage; a second input terminal configured to receive a second voltage, where the second voltage is greater than the first voltage; a third input / output control terminal configured as an input terminal or an output terminal; and a driving module for generating a driving voltage for driving the first power tube based on an input voltage received via the third input / output control terminal and the second voltage under the condition that the third input / output control terminal is configured as an input terminal, under the condition that the third input / output control terminal is configured as an output terminal, a driving voltage used for driving the first power tube is generated based on the first voltage and the second voltage; and the fourth output terminal is configured to drive the first power tube to be switched on and switched off through the driving voltage.

Description

Technical Field

[0001] The present application relates to the field of circuit technology, and more specifically, to a switch circuit and a control method of the switch circuit. Background Art

[0002] With the increasing complexity of application scenarios, higher requirements are placed on the safety and reliability of circuits. Simply realizing functions can no longer meet product requirements, so the diagnostic requirements for circuit functional safety are becoming increasingly higher.

[0003] Metal-oxide semiconductor (MOS) switching circuits typically use MOS switches to control the opening and closing of circuits to achieve the intended function (such as electrical timing). However, when the controlled voltage is important to the circuit, it often lacks safety and reliability. If the MOS switch encounters a fault such as a short circuit or an open circuit, it may cause loss of system function. External protection mechanisms such as voltage sampling and monitoring cannot cover all failure modes, resulting in poor safety. Therefore, a more comprehensive solution is needed to achieve compatibility with monitoring and diagnostic functions. Summary of the invention

[0004] In one aspect, an embodiment of the present application provides a switching circuit, comprising: a first power tube; and a driving circuit, the driving circuit comprising: a first input terminal, the first input terminal being configured to receive a first voltage; a second input terminal, the second input terminal being configured to receive a second voltage, wherein the second voltage is greater than the first voltage; a third input / output control terminal, the third input / output control terminal being configured as an input terminal or an output terminal; and a driving module, the driving module generating a driving voltage for driving the first power tube based on an input voltage and a second voltage received via the third input / output control terminal when the third input / output control terminal is configured as an input terminal, and generating a driving voltage for driving the first power tube based on the first voltage and the second voltage when the third input / output control terminal is configured as an output terminal; a fourth output terminal, the fourth output terminal being configured to drive the first power tube on and off through the driving voltage.

[0005] In some implementations, the first power tube has a first end, a second end, and a third end, wherein the first end is connected to the fourth output terminal of the drive circuit, the second end is grounded via the first resistor, and the third end is connected to the third input / output control terminal of the drive circuit.

[0006] In some implementations, the first power tube is a metal oxide semiconductor (MOS) transistor, the first end of the first power tube is the gate of the MOS transistor, the second end of the first power tube is the drain of the MOS transistor, and the third end of the first power tube is the source of the MOS transistor.

[0007] In some implementations, the first voltage is a supply voltage for the driving circuit, and the second voltage is a main power supply voltage for the driving circuit.

[0008] In some implementations, the third input / output control terminal is further connected to ground via a second resistor.

[0009] In some implementations, the driving module includes: a second power tube, the second power tube having a first end, a second end and a third end, wherein the first end of the second power tube is connected to the third input / output control terminal via a third resistor and is connected to the first input terminal via a third resistor and a fourth resistor, the second end of the second power tube is grounded, the third end of the second power tube is connected to the second input terminal via a fifth resistor, wherein a connection point between the first end of the second power tube and the third resistor is grounded via a sixth resistor; and a third power tube, the third power tube having a first end, a second end and a third end, wherein the first end of the third power tube is connected to the third end of the second power tube via a seventh resistor, the second end of the third power tube is grounded via an eighth resistor and also serves as a fourth output terminal, and wherein the third end of the third power tube is connected to the second input terminal.

[0010] In some implementations, the second power tube is an NPN transistor, wherein the first end of the second power tube is the base of the NPN transistor, the second end of the second power tube is the emitter of the NPN transistor, and the third end of the second power tube is the collector of the NPN transistor.

[0011] In some implementations, the third power tube is a MOS transistor, wherein the first end of the third power tube is the gate of the MOS transistor, the second end of the third power tube is the drain of the MOS transistor, and the third end of the third power tube is the source of the MOS transistor.

[0012] In some implementations, the third power tube and the first power tube are the same transistor.

[0013] In some implementations, the resistance of the second resistor is greater than the resistance of the fourth resistor, so that the divided voltage across the second resistor can be greater than the divided voltage across the fourth resistor.

[0014] In some implementations, the resistance values ​​of the second resistor, the third resistor, and the sixth resistor are equal to each other, and the resistance values ​​of the first resistor, the fourth resistor, and the eighth resistor are equal to each other.

[0015] In another aspect, an embodiment of the present application provides a control method for a switching circuit, wherein the switching circuit includes a first power tube and a driving circuit, the driving circuit includes an input / output control terminal, and the input / output control terminal can be configured as an input terminal or an output terminal, and the control method includes: configuring the input / output control terminal as an input terminal or an output terminal; when the input / output control terminal is used as an input terminal: generating a driving voltage for driving the first power tube based on an input voltage received by the input / output control terminal and a main power supply voltage of the driving circuit, and driving the first power tube to be turned on and off by the driving voltage; and monitoring the state of the switching circuit based on the input voltage and the driving voltage received by the input / output control terminal; when the input / output control terminal is used as an output terminal: generating a driving voltage for driving the first power tube based on a power supply voltage of the driving circuit and a main power supply voltage, and driving the first power tube to be turned on and off by the driving voltage; and providing different output voltages through the input / output control terminal in response to the first power tube being turned on and off.

[0016] In some implementations, the first power transistor is a metal oxide semiconductor (MOS) transistor.

[0017] In some implementations, monitoring the state of a switching circuit based on an input voltage and a drive voltage received by an input / output control terminal includes: when a level of an input voltage received by the input / output control terminal is lower than a first predetermined threshold and a level of a drive voltage is higher than a second predetermined threshold, determining that a short circuit exists in the drive circuit; when a level of an input voltage received by the input / output control terminal is lower than a first predetermined threshold and a level of a drive voltage is lower than a third predetermined threshold, determining that the drive circuit is turned off; when a level of an input voltage received by the input / output control terminal is higher than a first predetermined threshold and a level of a drive voltage is lower than a third predetermined threshold, determining that an open circuit exists in the drive circuit; and when a level of an input voltage received by the input / output control terminal is higher than a first predetermined threshold and a level of a drive voltage is higher than a second predetermined threshold, determining that the drive circuit is turned on, wherein the third predetermined threshold is less than or equal to the second predetermined threshold.

[0018] In some implementations, the control method of the switching circuit according to the embodiment of the present application also includes: when the input / output control terminal is used as the output terminal: when the level of the output voltage provided by the input / output control terminal is lower than a first predetermined threshold, determining that there is an open circuit in the drive circuit.

[0019] According to the switch circuit and the control method of the switch circuit of the embodiment of the present application, the input and output are compatible through a single input / output control terminal. When the single input / output control terminal is used as an input, the consistency between the expected state and the actual state of the circuit can be monitored; when used as an output, the expected circuit switch control can be achieved, so only a small amount of resources are needed to achieve the integration of control and diagnosis, and the safety and reliability of the circuit function are enhanced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solution of the embodiment of the present application, the following briefly describes the drawings involved in the embodiment of the present application. For ordinary technicians in this field, other drawings can also be obtained based on these drawings without creative work. In the drawings:

[0021] Figure 1 A schematic diagram of a switch circuit according to an embodiment of the present application is shown;

[0022] Figure 2 A specific circuit diagram of a switch circuit according to an embodiment of the present application is shown; and

[0023] Figure 3 A flow chart of a method for controlling a switch circuit according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0024] The features and exemplary embodiments of various aspects of the application will be described in detail below. In order to make the purpose, scheme, and advantages of the application clearer, the details of the application are further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the application and are not intended to limit the application. For those skilled in the art, the application can be implemented without some of the details in these specific details. The following description of the embodiments is only to provide a better understanding of the application by illustrating the example of the application.

[0025] It should be noted that, in this article, relational terms such as first, second, third, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. In addition, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, including a process, method, article or device of a series of elements not only including these elements, but also including other elements not explicitly listed, or also including elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the statement "include..." do not exclude the presence of other elements in the process, method, article or device including the elements.

[0026] Embodiments of the present application will now be described with reference to the accompanying drawings. Figure 1 FIG. 1 is a schematic diagram of a switch circuit according to an embodiment of the present application. Figure 1 As shown, the switch circuit 100 according to the embodiment of the present application includes a first power tube 11 and a drive circuit 12 .

[0027] like Figure 1 As shown, the driving circuit 12 includes: a first input terminal 121, which is configured to receive a first voltage VCC; a second input terminal 122, which is configured to receive a second voltage V-BATT, wherein the second voltage V-BATT is greater than the first voltage VCC; a third input / output control terminal 123, which is configured as an input terminal or an output terminal; and a driving module 124, which generates a driving voltage Vo for driving the first power tube 11 based on an input voltage ENA and a second voltage V-BATT received via the third input / output control terminal 123 when the third input / output control terminal 123 is configured as an input terminal, and generates a driving voltage Vo for driving the first power tube based on the first voltage VCC and the second voltage V-BATT when the third input / output control terminal 123 is configured as an output terminal; a fourth output terminal 125, which is configured to drive the first power tube 11 to turn on and off through the driving voltage Vo.

[0028] In some implementations, the first power tube 11 has a first end 111, a second end 112 and a third end 113, wherein the first end 111 is connected to the fourth output terminal 125 of the drive circuit 12, the second end 112 is grounded via a first resistor, and the third end 113 is connected to the third input / output control terminal 123 of the drive circuit 12.

[0029] In some implementations, the first power tube 11 is a metal oxide semiconductor (MOS) transistor, a first end of the first power tube 11 is a gate of the MOS transistor, a second end of the first power tube 11 is a drain of the MOS transistor, and a third end of the first power tube 11 is a source of the MOS transistor. In some implementations, the first power tube 11 may be a metal oxide semiconductor field effect (MOSFET) transistor.

[0030] In some implementations, the first voltage is a supply voltage for the driving circuit 12 , and the second voltage is a main power supply voltage for the driving circuit 12 .

[0031] In some implementations, the third input / output control terminal 123 is further connected to ground via a second resistor.

[0032] In some implementations, the driving module 124 includes: a second power tube, the second power tube having a first end, a second end and a third end, wherein the first end of the second power tube is connected to the third input / output control terminal via a third resistor and is connected to the first input terminal via a third resistor and a fourth resistor, the second end of the second power tube is grounded, the third end of the second power tube is connected to the second input terminal via a fifth resistor, wherein the connection point between the first end of the second power tube and the third resistor is grounded via a sixth resistor; and a third power tube, the third power tube having a first end, a second end and a third end, wherein the first end of the third power tube is connected to the third end of the second power tube via a seventh resistor, the second end of the third power tube is grounded via an eighth resistor and also serves as a fourth output terminal, and wherein the third end of the third power tube is connected to the second input terminal.

[0033] In some implementations, the second power tube is an NPN transistor, wherein the first end of the second power tube is the base of the NPN transistor, the second end of the second power tube is the emitter of the NPN transistor, and the third end of the second power tube is the collector of the NPN transistor.

[0034] In some implementations, the third power tube is a MOS transistor, wherein the first end of the third power tube is the gate of the MOS transistor, the second end of the third power tube is the drain of the MOS transistor, and the third end of the third power tube is the source of the MOS transistor.

[0035] In some implementations, the third power tube and the first power tube may be the same transistor.

[0036] In some implementations, the resistance of the second resistor is greater than the resistance of the fourth resistor, so that the divided voltage across the second resistor can be greater than the divided voltage across the fourth resistor. In some implementations, the resistance of the second resistor, the resistance of the third resistor, and the resistance of the sixth resistor are equal to each other, and the resistance of the first resistor, the resistance of the fourth resistor, and the resistance of the eighth resistor are equal to each other.

[0037] Figure 2 FIG. 2 shows a specific circuit diagram of a switch circuit according to an embodiment of the present application. Figure 2 As shown, the switch circuit 200 according to the embodiment of the present application includes a first power tube M1 and a driving circuit (other parts except the first power tube M1 are also called a micro control unit (MCU)).

[0038] like Figure 2As shown, the driving circuit includes: a first input terminal 221, which is configured to receive a first voltage VCC; a second input terminal 222, which is configured to receive a second voltage V-BATT, wherein the second voltage V-BATT is greater than the first voltage VCC (for example, the first voltage VCC is 5V, and the second voltage V-BATT is 12V); a third input / output control terminal 223, which is configured as an input terminal or an output terminal; and a driving module (the core part of the driving circuit, which will be described in detail below), which The block generates a driving voltage Vo for driving the first power tube M1 based on the input voltage ENA and the second voltage V-BATT received via the third input / output control terminal 223 when the third input / output control terminal 223 is configured as an input terminal, and generates a driving voltage Vo for driving the first power tube M1 based on the first voltage VCC and the second voltage V-BATT when the third input / output control terminal 223 is configured as an output terminal; a fourth output terminal 224, which is configured to drive the first power tube M1 to be turned on and off by the driving voltage Vo.

[0039] like Figure 2 As shown, in some implementations, the first power tube M1 has a first end, a second end and a third end, wherein the first end is connected to the fourth output terminal 224 of the drive circuit, the second end is grounded via the first resistor R11 (e.g., 1 kΩ), and the third end is connected to the third input / output control terminal 223 of the drive circuit.

[0040] In some implementations, the first power tube M1 may be a metal oxide semiconductor (MOS) transistor, the first end of the first power tube M1 is the gate of the MOS transistor, the second end of the first power tube M1 is the drain of the MOS transistor, and the third end of the first power tube M1 is the source of the MOS transistor. The first power tube M1 may be a PMOS tube. In some implementations, the first power tube M1 may be a metal oxide semiconductor field effect (MOSFET) transistor.

[0041] In some implementations, the first voltage VCC is a power supply voltage for the drive circuit, that is, a voltage that ensures that the drive circuit can be powered on, and the second voltage V-BATT is a main power supply voltage for the drive circuit, an input operating voltage of the drive circuit. Generally, the main power supply voltage is higher than the power supply voltage.

[0042] In some implementations, the third input / output control terminal 223 is further grounded via a second resistor R2 (eg, 10 kΩ).

[0043] In some implementations, the driving module includes: a second power tube Q2, the second power tube Q2 having a first end, a second end and a third end, wherein the first end of the second power tube Q2 is connected to the third input / output control terminal 223 via a third resistor R3 (for example, 10 kΩ) and connected to the first input terminal 221 via a third resistor R3 (for example, 10 kΩ) and a fourth resistor R4 (for example, 1 kΩ), the second end of the second power tube Q2 is grounded, and the third end of the second power tube Q2 is connected to the second input terminal 222 via a fifth resistor R5 (for example, 100 kΩ), wherein the The connection point between the first end of the second power tube Q2 and the third resistor R3 (for example, 10kΩ) is grounded via a sixth resistor R6 (for example, 10kΩ); and a third power tube M2, which has a first end, a second end and a third end, wherein the first end of the third power tube M2 is connected to the third end of the second power tube Q2 via a seventh resistor R7 (for example, 33Ω), the second end of the third power tube M2 is grounded via an eighth resistor R8 (for example, 1k) and also serves as a fourth output terminal 224, and wherein the third end of the third power tube M2 is connected to the second input terminal 222.

[0044] In some implementations, the second power tube Q2 is an NPN transistor, wherein the first end of the second power tube Q2 is the base of the NPN transistor, the second end of the second power tube is the emitter of the NPN transistor, and the third end of the second power tube is the collector of the NPN transistor.

[0045] In some implementations, the third power tube M2 is a MOS transistor, wherein the first end of the third power tube M2 is the gate of the MOS transistor, the second end of the third power tube M2 is the drain of the MOS transistor, and the third end of the third power tube M2 is the source of the MOS transistor.

[0046] In some implementations, the third power transistor M2 and the first power transistor M2 may be the same transistor, for example, both are MOS transistors.

[0047] In some implementations, the resistance of the second resistor R2 is greater than the resistance of the fourth resistor R4, so that the voltage across the second resistor R2 can be greater than the voltage across the fourth resistor R4. Figure 2 As shown, as can be seen from the resistor series voltage division, the voltage across the fourth resistor R4 is smaller than the voltage across the second resistor R2 (ie, the ENA voltage), which is used as a basis for determining whether the logic value is high or low as described below.

[0048] In some implementations, the resistance values ​​of the second resistor R2, the third resistor R3, and the sixth resistor R6 may be equal to each other, and the resistance values ​​of the first resistor R1, the fourth resistor R4, and the eighth resistor R8 may be equal to each other.

[0049] It should be understood that although Figure 2 The resistance values ​​of various resistors are shown and described here. These are only used as examples to facilitate the implementation of the technical solutions of the embodiments of the present application by those skilled in the art, and should not be a limitation to the present application. In practical applications, those skilled in the art can set the value according to the actual voltage level of the circuit, but it should be noted that it should not be too small. It should be understood that the resistance value of the fifth resistor R5 can be set to be relatively large, because considering that the main power supply voltage V-BATT is relatively large, the fifth resistor can be set to be larger to provide current limiting protection for other devices. At the same time, the main power supply voltage V-BATT is the input voltage of the switching circuit, so the fifth resistor can be set to be larger to reduce static power consumption. It should also be understood that when the third input / output control terminal 223 is configured as an output terminal, the third input / output control terminal 223 should be set to a high impedance state. It should also be understood that in order to avoid obscuring the present application, some components used to improve the signal quality or protection devices are not in Figure 2 As shown in FIG. 1 , for example, a gate clamp or a Zener diode of the third power tube M2 , related devices may be added in combination with specific applications.

[0050] like Figure 2 As shown, after the switch circuit 200 according to the embodiment of the present application is powered on, a predetermined power supply voltage VCC and a main power supply voltage V-BATT are obtained respectively.

[0051] In the case where the input / output control terminal 223 is used as an input terminal (MCU outputs at this time), when the level of the input voltage ENA of the input / output control terminal 223 is high, the voltage of the base of the second power tube Q2 (such as an NPN transistor) is higher than the voltage of its emitter (the emitter is grounded), so that the second power tube Q2 is turned on. At this time, the voltage of the gate of the third power tube M2 is lower than the voltage V-BATT of its source, so that the third power tube M2 is turned on. The driving voltage Vo is equal to the main power supply voltage V-BATT, and the driving circuit is turned on (that is, the third power tube M2 is actively turned on). Since the driving voltage Vo is greater than the predetermined power supply voltage VCC, the voltage of the gate of the first transistor M1 is greater than the voltage of its source, so that the first transistor M1 is turned off.

[0052] When the level of the input voltage ENA of the input / output control terminal 223 is low, the voltage of the base of the second power tube Q2 is lower than the voltage of its emitter, so that the second power tube Q2 is turned off. At this time, the voltage of the gate of the third power tube M2 is equal to the voltage of its source, so that the third power tube M2 is turned off. The driving voltage Vo is equal to 0V, and the driving circuit is turned off (that is, the third power tube M2 is actively turned off). Since the driving voltage Vo is less than the predetermined power supply voltage VCC, the voltage of the gate of the first transistor M1 is less than the voltage of its source, so that the first transistor M1 is turned on.

[0053] As described above, the input voltage ENA based on the input / output control terminal 223 and the second input voltage V-BATT control the on and off of the second power tube Q2 and the third power tube M2, thereby generating a driving voltage Vo to control the on and off of the first power tube M1. It should be understood that in the case where the input / output control terminal 223 is used as an input terminal, the voltage Vo is also the output voltage of the switch circuit.

[0054] If the third power tube M2 is in a short-circuit state, the driving voltage Vo maintains the main power supply voltage V-BATT regardless of the level state of the input / output control terminal 223. Therefore, when the input voltage ENA of the input / output control terminal 223 is at a low level but the driving voltage Vo is not equal to 0, it can be determined that the third power tube M2 is in a short-circuit state.

[0055] If the third power tube M2 is in an open circuit state, the driving voltage Vo remains at 0 V regardless of the level state of the input / output control terminal 223. Therefore, when the input voltage ENA of the input / output control terminal 223 is at a high level ENA but the driving voltage Vo is equal to 0, it can be determined that the third power tube M2 is in an open circuit state. It is worth noting that the same result occurs when the third resistor R3, the second power tube Q2 or the seventh resistor R7 is open circuited (herein collectively referred to as the driving circuit open circuit).

[0056] Based on the above explanation, it is assumed that the input voltage ENA of the input / output control terminal 223 is divided by 3V, that is, the high level is higher than 3V, the state is 1, and the low level is lower than 3V, the state is 0. Similarly, the high and low levels of the driving voltage Vo can be set to 1 and 0 (the dividing line can be selected independently, for example, below 2.5V, the state is 0, and above 3.5V, the state is 1), and the following truth table can be obtained:

[0057] Table 1

[0058] ENA V diagnosis 0 0 Drive circuit off 0 1 M2 short circuit 1 0 Drive circuit open 1 1 Drive circuit conduction

[0059] On the other hand, when the input / output control terminal 223 is used as an output terminal (MCU performs input at this time), when the base of the second power tube Q2 is pulled up to the predetermined power supply voltage VCC, the voltage of the base is higher than the voltage of its emitter, so that the second power tube Q2 is turned on. At this time, the voltage of the gate of the third power tube M2 is lower than the voltage of its source, so that the third power tube M2 is turned on. The driving voltage Vo is equal to the main power supply voltage V-BATT, and the driving circuit is turned on. Since the driving voltage Vo is greater than the predetermined power supply voltage VCC, the voltage of the gate of the first transistor M1 is greater than the voltage of its source, so that the first transistor M1 is turned off. At this time, the third resistor R3 and the sixth resistor R6 are connected in series and in parallel with the second resistor R2, and then connected in series with the fourth resistor R4 to form a voltage divider circuit, and an ENA voltage of about 4.4V is obtained at the input / output control terminal 223 (taking the VCC voltage shown in the figure as 5V and the resistance value shown in the figure as an example).

[0060] If the third power tube M2 is in an open circuit state, the driving voltage Vo is equal to 0V. Since the driving voltage Vo is less than the predetermined power supply voltage VCC, the voltage of the gate of the first transistor M1 is less than the voltage of its source, so that the first transistor M1 is turned on. At this time, the third resistor R3 and the sixth resistor R6 are connected in series and in parallel with the second resistor R2 and the first resistor R1, and then connected in series with the fourth resistor R4 to form a voltage divider circuit, and an ENA voltage of about 2.2V is obtained at the input / output control terminal 223 (taking the VCC voltage shown in the figure as 5V and the resistance value shown in the figure as an example). It is worth noting that the same result is obtained when the third resistor R3, the second power tube Q2 or the seventh resistor R7 is open.

[0061] As described above, the on and off of the second power tube Q2 and the third power tube M2 are controlled based on the first voltage VCC and the second input voltage V-BATT, thereby generating a driving voltage Vo to control the on and off of the first power tube M2, thereby generating a specific output. It should also be understood that when the input / output control terminal 223 is used as an output terminal, it is also possible to detect whether the driving circuit is open. As shown above, under normal circumstances, the state of the driving voltage Vo should be 1, and the state of the voltage ENA is also 1. When the driving circuit is open and causes the driving voltage Vo to be 0V, the state of the voltage ENA becomes 0, so the circuit state can be diagnosed by the state of the voltage ENA of the input / output control terminal.

[0062] It should be understood that the above specific examples are only illustrative examples of the present application and should not be regarded as limiting the present application. Those skilled in the art can set specific values ​​of various voltages and various thresholds based on the teachings of the present application and actual needs.

[0063] According to the switch circuit of the embodiment of the present application, the input and output are compatible through a single input / output control terminal. When used as an input, the consistency between the expected state and the actual state of the circuit can be monitored; when used as an output, the expected circuit switch control can be achieved, so only a small amount of resources are needed to achieve the integration of control and diagnosis, and the safety and reliability of the circuit function are enhanced. In addition, the switch circuit according to the embodiment of the present application is mainly composed of discrete devices, which is easy to implement and not complicated.

[0064] Figure 3 The control method of the switch circuit according to the embodiment of the present application can be applied to the above reference Figure 1 and Figure 2 The switching circuits 100 and 200 are described.

[0065] like Figure 3 As shown, the control method 300 of the switch circuit according to the embodiment of the present application includes: step S301: configuring the input / output control terminal as an input terminal or an output terminal. In the case where the input / output control terminal is used as an input terminal, the method flow proceeds to step S302, where a driving voltage for driving the first power tube is generated based on the input voltage received by the input / output control terminal and the main power supply voltage of the driving circuit. Next, the method flow proceeds to step S303, and the first power tube is driven to turn on and off by the driving voltage. Then, in step S304, the state of the switch circuit is monitored based on the input voltage and the driving voltage received by the input / output control terminal.

[0066] In the case where the input / output control terminal is used as an output terminal, the method proceeds to step S305, where a driving voltage for driving the first power tube is generated based on the power supply voltage of the driving circuit and the main power supply voltage. Next, the method proceeds to step S306, where the first power tube is driven on and off by the driving voltage. Then, in step S307, in response to the first power tube being turned on and off, different output voltages are provided through the input / output control terminal.

[0067] In some implementations, the first power transistor is a metal oxide semiconductor (MOS) transistor. In some implementations, the first power transistor may be a metal oxide semiconductor field effect (MOSFET) transistor.

[0068] In some implementations, monitoring the state of the switch circuit based on the input voltage and the drive voltage received by the input / output control terminal includes:

[0069] When the level of the input voltage received by the input / output control terminal is lower than a first predetermined threshold and the level of the driving voltage is higher than a second predetermined threshold, it is determined that there is a short circuit in the driving circuit;

[0070] When the level of the input voltage received by the input / output control terminal is lower than the first predetermined threshold and the level of the driving voltage is lower than the third predetermined threshold, it is determined that the driving circuit is turned off;

[0071] When the level of the input voltage received by the input / output control terminal is higher than a first predetermined threshold and the level of the driving voltage is lower than a third predetermined threshold, determining that an open circuit exists in the driving circuit; and

[0072] When the level of the input voltage received by the input / output control terminal is higher than the first predetermined threshold and the level of the driving voltage is higher than the second predetermined threshold, it is determined that the driving circuit is turned on, wherein the third predetermined threshold is less than or equal to the second predetermined threshold.

[0073] In some implementations, the control method 300 of the switching circuit according to the embodiment of the present application also includes: when the input / output control terminal is used as the output terminal: when the level of the output voltage provided by the input / output control terminal is lower than a first predetermined threshold, determining that there is an open circuit in the drive circuit.

[0074] According to the control method of the switching circuit of the embodiment of the present application, a single input / output control terminal is compatible with input and output. When configured as an input, the consistency between the expected state and the actual state of the circuit can be monitored; when configured as an output, the expected circuit switching control can be achieved. Therefore, only a small amount of resources are required to achieve the integration of control and diagnosis, thereby enhancing the safety and reliability of the circuit function.

[0075] Those skilled in the art will appreciate that the present application is not limited to the specific structures and steps described above and shown in the accompanying drawings. For the sake of simplicity, the description of known structures and methods is omitted herein. In the above-described embodiments, several specific steps are described and shown as examples. However, the method of the present application is not limited to the specific steps described and shown, and without departing from the scope of the present application, those skilled in the art can make various changes, modifications and additions to the embodiments of the present application, or change the order between the steps.

[0076] The above disclosed contents are only some specific embodiments of the present application. Those skilled in the art can understand that the protection scope of the present application is not limited thereto. Rather, various equivalent modifications or substitutions can be thought of within the technical scope disclosed in the present application, and these equivalent modifications or substitutions are all covered within the protection scope of the present application.

Claims

1. A switching circuit, comprising: The first power tube; and A driving circuit, the driving circuit comprising: a first input terminal configured to receive a first voltage; a second input terminal configured to receive a second voltage, wherein the second voltage is greater than the first voltage; a third input / output control terminal configured as an input terminal or an output terminal; and a driving module, the driving module generating a driving voltage for driving the first power tube based on an input voltage received via the third input / output control terminal and the second voltage when the third input / output control terminal is configured as an input terminal, and generating a driving voltage for driving the first power tube based on the first voltage and the second voltage when the third input / output control terminal is configured as an output terminal; A fourth output terminal is configured to drive the first power tube to be turned on and off through the driving voltage.

2. The switch circuit according to claim 1, wherein: The first power tube has a first end, a second end and a third end, wherein the first end is connected to the fourth output terminal of the drive circuit, the second end is grounded via a first resistor, and the third end is connected to the third input / output control terminal of the drive circuit.

3. The switch circuit according to claim 2, wherein: The first power tube is a metal oxide semiconductor (MOS) transistor, the first end of the first power tube is the gate of the MOS transistor, the second end of the first power tube is the drain of the MOS transistor, and the third end of the first power tube is the source of the MOS transistor.

4. The switch circuit according to claim 1, wherein: The first voltage is a supply voltage for the driving circuit, and the second voltage is a main power supply voltage for the driving circuit.

5. The switch circuit according to claim 1, wherein: The third input / output control terminal is also grounded via a second resistor.

6. The switch circuit according to any one of claims 1 to 5, wherein: The driving module comprises: a second power tube, the second power tube having a first end, a second end and a third end, wherein the first end of the second power tube is connected to the third input / output control terminal via a third resistor and connected to the first input terminal via the third resistor and a fourth resistor, the second end of the second power tube is grounded, the third end of the second power tube is connected to the second input terminal via a fifth resistor, wherein a connection point between the first end of the second power tube and the third resistor is grounded via a sixth resistor; and A third power tube, the third power tube having a first end, a second end and a third end, wherein the first end of the third power tube is connected to the third end of the second power tube via a seventh resistor, the second end of the third power tube is grounded via an eighth resistor and also serves as the fourth output terminal, and wherein the third end of the third power tube is connected to the second input terminal.

7. The switch circuit according to claim 6, wherein: The second power tube is an NPN transistor, wherein the first end of the second power tube is the base of the NPN transistor, the second end of the second power tube is the emitter of the NPN transistor, and the third end of the second power tube is the collector of the NPN transistor.

8. The switch circuit according to claim 6, wherein: The third power tube is a MOS transistor, wherein the first end of the third power tube is the gate of the MOS transistor, the second end of the third power tube is the drain of the MOS transistor, and the third end of the third power tube is the source of the MOS transistor.

9. The switch circuit according to claim 6, wherein: The third power tube and the first power tube are the same transistors.

10. The switch circuit according to claim 6, wherein: The resistance value of the second resistor is greater than the resistance value of the fourth resistor, so that the divided voltage across the second resistor can be greater than the divided voltage across the fourth resistor.

11. The switch circuit according to claim 6, wherein: The resistance values ​​of the second resistor, the third resistor, and the sixth resistor are equal to each other, and the resistance values ​​of the first resistor, the fourth resistor, and the eighth resistor are equal to each other.

12. A control method for a switch circuit, wherein the switch circuit comprises a first power tube and a drive circuit, the drive circuit comprises an input / output control terminal, the input / output control terminal can be configured as an input terminal or an output terminal, the control method comprises: configuring the input / output control terminal as an input terminal or an output terminal; In the case where the input / output control terminal is used as an input terminal: generating a driving voltage for driving the first power tube based on an input voltage received by the input / output control terminal and a main power supply voltage of the driving circuit, Driving the first power tube to turn on and off by the driving voltage; as well as monitoring a state of the switch circuit based on an input voltage received by the input / output control terminal and the drive voltage; In the case where the input / output control terminal is used as an output terminal: generating a driving voltage for driving the first power tube based on the power supply voltage of the driving circuit and the main power supply voltage, Driving the first power tube to turn on and off by the driving voltage; as well as In response to the first power tube being turned on and off, different output voltages are provided through the input / output control terminal.

13. The control method of the switch circuit according to claim 12, wherein: The first power tube is a metal oxide semiconductor (MOS) transistor.

14. The control method of the switch circuit according to claim 12 or 13, wherein: Monitoring the state of the switch circuit based on the input voltage received by the input / output control terminal and the driving voltage includes: When the level of the input voltage received by the input / output control terminal is lower than a first predetermined threshold and the level of the driving voltage is higher than a second predetermined threshold, it is determined that a short circuit exists in the driving circuit; When the level of the input voltage received by the input / output control terminal is lower than the first predetermined threshold and the level of the driving voltage is lower than a third predetermined threshold, it is determined that the driving circuit is turned off; When the level of the input voltage received by the input / output control terminal is higher than the first predetermined threshold and the level of the driving voltage is lower than the third predetermined threshold, determining that there is an open circuit in the driving circuit; and When the level of the input voltage received by the input / output control terminal is higher than the first predetermined threshold and the level of the driving voltage is higher than the second predetermined threshold, determining that the driving circuit is turned on, The third predetermined threshold is less than or equal to the second predetermined threshold.

15. The control method of the switch circuit according to claim 12 or 13, further comprising: In the case where the input / output control terminal is used as an output terminal: when the level of the output voltage provided by the input / output control terminal is lower than a first predetermined threshold, it is determined that there is an open circuit in the driving circuit.

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