Transistor-based switching circuit and electronic device

Abstract

A kind of transistor-based switching circuit and electronic equipment, belong to electronic circuit technical field, including first transistor, second transistor and drive circuit;First transistor and second transistor are connected in series, and the body diode of first transistor and the body diode of second transistor are oppositely connected and arranged;Resistance component is arranged between the drain of first transistor and the gate of first transistor and between the drain of second transistor and the gate of second transistor;Drive circuit accesses control signal, and according to control signal output drive signal, and in response to the stop of control signal, the output of drive signal is disconnected;First transistor and second transistor are opened according to drive signal, and are closed according to the disconnection of drive signal;Therefore, the possibility of leakage current is reduced.

Description

Technical Field

[0001] This application belongs to the field of electronic circuit technology, and in particular relates to a transistor-based switching circuit and electronic device. Background Technology

[0002] In electronic devices, to extend battery life and prevent overcharging or over-discharging, a switching circuit is needed to isolate the battery. This requires the switching circuit to both prevent charging and discharging the battery.

[0003] The related transistor-based switching circuits can only achieve unidirectional turn-off, that is, they can prevent current from flowing from the first terminal of the switching circuit to the first terminal of the switching circuit, but they cannot prevent current from flowing in the reverse direction from the second terminal of the switching circuit to the first terminal of the switching circuit, which leads to a large leakage current.

[0004] Therefore, the leakage current of the related transistor-based switching circuits is large. Summary of the Invention

[0005] The purpose of this application is to provide a transistor-based switching circuit and an image sensor, aiming to solve the problem of large leakage current in related transistor-based switching circuits.

[0006] This application provides a transistor-based switching circuit, including a first transistor, a second transistor, and a driving circuit;

[0007] The first transistor and the second transistor are connected in series, and the body diodes of the first transistor and the second transistor are connected opposite to each other.

[0008] A resistor assembly is provided between the drain and gate of the first transistor and between the drain and gate of the second transistor.

[0009] The driving circuit is connected to the resistor assembly, the gate of the first transistor, and the gate of the second transistor. It is used to receive a control signal and output a driving signal according to the control signal to drive the first transistor and the second transistor to turn on. In response to the cessation of the control signal, the output of the driving signal is disconnected.

[0010] The first transistor and the second transistor are configured to turn on in response to the drive signal and turn off in response to the disconnection of the drive signal.

[0011] This invention also provides an electronic device, which includes the transistor-based switching circuit described above.

[0012] The beneficial effects of the embodiments of the present invention compared with the prior art are as follows: since the body diodes of the first transistor and the second transistor are connected in opposite directions, the first transistor and the second transistor connected in series have a bidirectional cutoff function when the drive signal is disconnected, reducing the possibility of leakage current. Attached Figure Description

[0013] To more clearly illustrate the technical inventions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 A schematic diagram of a transistor-based switching circuit provided in an embodiment of this application;

[0015] Figure 2 This is a schematic diagram of another structure of a transistor-based switching circuit provided in an embodiment of this application;

[0016] Figure 3 This is a schematic diagram of another structure of a transistor-based switching circuit provided in an embodiment of this application;

[0017] Figure 4 This is a schematic diagram of another structure of a transistor-based switching circuit provided in an embodiment of this application;

[0018] Figure 5 A partial example circuit schematic of a transistor-based switching circuit provided in an embodiment of this application;

[0019] Figure 6 Another example circuit schematic of a transistor-based switching circuit provided in one embodiment of this application;

[0020] Figure 7 Another example circuit schematic of a transistor-based switching circuit provided in one embodiment of this application;

[0021] Figure 8 This is a partial example circuit schematic of a transistor-based switching circuit provided in one embodiment of this application. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Figure 1 A schematic diagram of a transistor-based switching circuit according to a preferred embodiment of this application is shown. For ease of explanation, only the parts relevant to this embodiment are shown, and are described in detail below:

[0027] The transistor-based switching circuit described above includes a first transistor 10, a second transistor 20, and a driving circuit 30.

[0028] The first transistor 10 and the second transistor 20 are connected in series, and the body diodes of the first transistor 10 and the second transistor 20 are connected relative to each other.

[0029] A resistor assembly (not shown in the figure) is provided between the drain and gate of the first transistor 10 and between the drain and gate of the second transistor 20.

[0030] The driving circuit 30 is connected to the resistor assembly, the gate of the first transistor 10, and the gate of the second transistor 20. It is used to receive control signals and output driving signals according to the control signals to drive the first transistor 10 and the second transistor 20 to turn on. In response to the stop of the control signals, the output of the driving signals is disconnected.

[0031] The first transistor 10 and the second transistor 20 are used to turn on according to a drive signal and turn off according to the disconnection of the drive signal.

[0032] It should be noted that there are two cases for the transistor-based switching circuit described above.

[0033] In the first case, both the first transistor 10 and the second transistor 20 are P-channel metal oxide semiconductor (PMOS) transistors, and the drive signal is low level.

[0034] In the second case, both the first transistor 10 and the second transistor 20 are N-channel metal oxide semiconductor (NMOS) transistors, and the drive signal is high level.

[0035] Understandably, when the control signal input is stopped, the drive circuit 30 disconnects the drive signal output, thereby turning off the first transistor 10 and the second transistor 20. Since the body diodes of the first transistor 10 and the second transistor 20 are connected relative to each other, the first transistor 10 and the second transistor 20 connected in series have a bidirectional cutoff function when the drive signal is disconnected, reducing the possibility of leakage current.

[0036] like Figure 2 As shown, the transistor-based switching circuit also includes a first protection circuit 80 and a second protection circuit 90.

[0037] The first protection circuit 80 is connected between the drain and source of the first transistor 10 and is used to protect the current flowing through the first transistor 10. Specifically, the first protection circuit 80 is used to break down and release energy in response to the voltage between the drain and source of the first transistor 10 being greater than a preset voltage.

[0038] The second protection circuit 90 is connected between the drain and source of the second transistor 20 and is used to protect the current flowing through the second transistor 20. Specifically, the second protection circuit 90 is used to break down and release energy in response to the voltage between the drain and source of the second transistor 20 being greater than a preset voltage.

[0039] The first protection circuit 80 and the second protection circuit 90 can both be TVS diodes. TVS diodes have the characteristics of bidirectional overvoltage protection, strong instantaneous overload capacity, extremely fast response speed, large power absorption, small leakage current, and stable clamping voltage. They can be used as fast release components.

[0040] The above technical solution can quickly release surge power when a transient high voltage passes through, effectively protecting the first and second transistors.

[0041] In one embodiment, the transistor-based switching circuit described above further includes a voltage regulator circuit.

[0042] A voltage regulator circuit is connected between the drain and gate of the first transistor 10 and between the drain and gate of the second transistor 20, for regulating the voltage between the drain and gate of the first transistor 10 and the voltage between the drain and gate of the second transistor 20.

[0043] It is understandable that a voltage regulator circuit may include a Zener diode.

[0044] Through the above technical solution, when a transient high voltage passes through, the voltage between the drain and gate of the transistor is stabilized, effectively protecting the first transistor 10 and the second transistor 20.

[0045] like Figure 3 As shown, the transistor-based switching circuit described above also includes a control circuit 40.

[0046] The control circuit 40 is connected to the drive circuit 30 and is used to output control signals.

[0047] Through the above technical solution, the control circuit 40 can output control signals according to specific needs to realize the control function of the transistor-based switching circuit.

[0048] like Figure 4 As shown, the transistor-based switching circuit also includes an energy storage circuit 50 and a load 60.

[0049] The energy storage circuit 50, connected to the second transistor 20 and the second resistor assembly 02, is used to output direct current for power supply. In one embodiment, the energy storage circuit 50 can be a battery assembly.

[0050] The load 60 is connected to the charging circuit 70, the first transistor 10 and the first resistor assembly 01, and is used to operate according to the DC power supply.

[0051] The first transistor 10 and the second transistor 20 are used to transmit DC power according to the drive signal.

[0052] Through the above technical solution, the energy storage circuit 50 supplies power to the load 60. It can be understood that when the drive signal is disconnected, the first transistor 10 and the second transistor 20 are turned off. Since the body diodes of the first transistor 10 and the second transistor 20 are connected in a relative manner, the series-connected first transistor 10 and second transistor 20 have a bidirectional turn-off function, thereby reducing the possibility of leakage current of the supplied DC power.

[0053] Please continue to refer to this. Figure 4The transistor-based switching circuit described above also includes a charging circuit 70.

[0054] The charging circuit 70 is connected to the first transistor 10 and the first resistor assembly 01 and is used to output charging DC power.

[0055] The energy storage circuit 50 is also used for charging based on the charging DC power.

[0056] The 60-load unit is also used to operate based on the DC power supply for charging.

[0057] The first transistor 10 and the second transistor 20 are also used to transmit charging DC power according to the drive signal.

[0058] It should be noted that the charging circuit 70 may include a switching power supply, an LLC resonant converter, and a DC-DC output circuit based on PWM control.

[0059] Through the above technical solution, the charging circuit 70 charges the energy storage circuit 50. It can be understood that when the drive signal is disconnected, the first transistor 10 and the second transistor 20 are cut off. Since the body diodes of the first transistor 10 and the second transistor 20 are connected in a relative manner, the series-connected first transistor 10 and second transistor 20 have a bidirectional cut-off function, thereby reducing the possibility of leakage current of the charging DC power.

[0060] In one embodiment, when the drive circuit 30 disconnects the output of the drive signal in response to the stop of the control signal, the first transistor 10 and the second transistor 20 are also used to stop transmitting charging DC and supply DC in response to the disconnection of the drive signal.

[0061] With the above technical solution, when the drive signal is disconnected, the first transistor 10 and the second transistor 20 are turned off. Since the body diodes of the first transistor 10 and the second transistor 20 are connected in opposite directions, the series-connected first transistor 10 and second transistor 20 have a bidirectional turn-off function, thereby reducing the possibility of leakage current of charging DC and supply DC.

[0062] Figure 5 The illustration shows a partial example circuit structure of a transistor-based switching circuit provided in an embodiment of the present invention. Figure 6 This illustration shows another partial example circuit structure of a transistor-based switching circuit provided in an embodiment of the present invention. Figure 7 This illustrates another example circuit structure of the transistor-based switching circuit provided in an embodiment of the present invention. Figure 8 Another example circuit structure of the transistor-based switching circuit provided in the embodiment of the present invention is shown. For ease of explanation, only the parts related to the embodiment of the present invention are shown, and are described in detail below:

[0063] like Figure 5 As shown, a first resistor assembly 01 is disposed between the drain and the gate of the first transistor 10; a second resistor assembly 02 is disposed between the drain and the gate of the second transistor 20.

[0064] The first transistor 10 is the first PMOS transistor P1, and the second transistor 20 is the second PMOS transistor P2.

[0065] The source of the first PMOS transistor P1, the cathode of the body diode of the first PMOS transistor P1, and the first end of the first resistor assembly 01 are connected and together form the first input / output terminal of the switching circuit; the source of the second PMOS transistor P2, the cathode of the body diode of the second PMOS transistor P2, and the first end of the second resistor assembly 02 are connected and together form the second input / output terminal of the switching circuit; the gate of the first PMOS transistor P1, the gate of the second PMOS transistor P2, the second end of the first resistor assembly 01, and the second end of the second resistor assembly 02 are all connected to the driving circuit 30; the drain of the first PMOS transistor P1 is connected to the anode of the body diode of the first PMOS transistor P1, the drain of the second PMOS transistor P1, and the anode of the body diode of the second PMOS transistor P2.

[0066] The first resistor assembly 01 includes a first resistor R1, and the second resistor assembly 02 includes a second resistor R2.

[0067] like Figure 6 As shown, a third resistor assembly 03 is provided between the drain and gate of the first transistor 10 and between the drain and gate of the second transistor 20.

[0068] The first transistor 10 is the third PMOS transistor P3, and the second transistor 20 is the fourth PMOS transistor P4;

[0069] The drain of the third PMOS transistor P3 and the anode of its body diode are connected together to form the first input / output terminal of the switching circuit; the drain of the fourth PMOS transistor P4 and the anode of its body diode are connected together to form the second input / output terminal of the switching circuit; the source of the third PMOS transistor P3 is connected to the first terminal of the third resistor assembly 03, the cathode of the body diode of the third PMOS transistor P3, the source of the fourth PMOS transistor P4, and the cathode of its body diode; the gates of the third PMOS transistor P3, the fourth PMOS transistor P4, and the second terminal of the third resistor assembly 03 are all connected to the driving circuit 30 to receive the driving signal.

[0070] The third resistor assembly 03 includes a third resistor R3.

[0071] like Figure 5 and Figure 6 As shown, the driving circuit 30 includes a first field-effect transistor M1 and a first current-limiting resistor Rs1.

[0072] The gate of the first field-effect transistor M1 and the first end of the first current-limiting resistor Rs1 are connected and together form the input terminal of the driving circuit 30 to receive the control signal; the drain of the first field-effect transistor M1 forms the output terminal of the driving circuit 30 and is connected to the gate of the first transistor 10 and the gate of the second transistor 20 to output the driving signal; the source of the first field-effect transistor M1 and the second end of the first current-limiting resistor Rs1 are connected to the power supply ground.

[0073] Understandable Figure 5 and Figure 6 The transistor-based switching circuit shown can be applied to the switching on and off of the positive DC bus, utilizing its conduction characteristics to control the on / off state of the main circuit. Compared to NMOS, PMOS has unique advantages in positive power supply control and is suitable for scenarios where grounding needs to be avoided.

[0074] like Figure 5 and 6 As shown, the first transistor 10 and the second transistor 20 are connected in series between the first node A and the second node B, wherein the first transistor 10 is connected to the first node A and the second transistor 20 is connected to the second node B.

[0075] The transistor-based switching circuit also includes a first clamping circuit 110.

[0076] The first clamping circuit 110 is connected to the driving circuit 30, the first node A and the second node B, and is used to clamp the voltage between the first node A and the second node B according to the driving signal.

[0077] The first clamping circuit 110 includes a sixth NMOS transistor N6, a seventh NMOS transistor N7, a ninth PMOS transistor P9, an eighth NMOS transistor N8, and a ninth NMOS transistor N9.

[0078] The source and gate of the sixth NMOS transistor N6 are connected to the power supply ground. The drain of the sixth NMOS transistor N6 is connected to the source of the seventh NMOS transistor N7. The drain of the seventh NMOS transistor N7 is connected to the drain of the ninth PMOS transistor P9, the source of the eighth NMOS transistor N8, and the source of the ninth NMOS transistor N9. The gates of the seventh NMOS transistor N7, the ninth PMOS transistor P9, and the ninth NMOS transistor N9 are used together as the drive signal input terminal of the first clamping circuit 110 to input the drive signal. The drain of the ninth NMOS transistor N9 is connected to the first node A, and the gate of the eighth NMOS transistor N8 is connected to the second node B. The source of the ninth PMOS transistor P9 and the drain of the eighth NMOS transistor N8 are connected to the first power supply VAA.

[0079] like Figure 7 As shown, a fourth resistor assembly 04 is provided between the drain and the gate of the first transistor 10; a fifth resistor assembly 05 is provided between the drain and the gate of the second transistor 20; the first transistor 10 is a first NMOS transistor N1, and the second transistor 20 is a second NMOS transistor N2.

[0080] The source of the first NMOS transistor N1, the cathode of the body diode of the first NMOS transistor N1, and the first end of the fourth resistor assembly 04 are connected and together form the first input / output terminal of the switching circuit; the source of the second NMOS transistor N2, the cathode of the body diode of the second NMOS transistor N2, and the first end of the fifth resistor assembly 05 are connected and together form the second input / output terminal of the switching circuit; the gate of the first NMOS transistor N1, the gate of the second NMOS transistor N2, the second end of the fourth resistor assembly 04, and the second end of the fifth resistor assembly 05 are all connected to the driving circuit 30 to receive the driving signal; the drain of the first NMOS transistor N1 is connected to the anode of the body diode of the first NMOS transistor N1, the drain of the second NMOS transistor N2, and the anode of the body diode of the second NMOS transistor N2.

[0081] The fourth resistor assembly 04 includes a fourth resistor R4, and the fifth resistor assembly 05 includes a fifth resistor R5.

[0082] like Figure 8 As shown, a sixth resistor assembly 06 is provided between the drain and gate of the first transistor 10 and between the drain and gate of the second transistor 20; the first transistor 10 is a second NMOS transistor N3, and the second transistor 20 is a fourth NMOS transistor N4.

[0083] The source of the second NMOS transistor N3 and the anode of its body diode are connected together to form the first input / output terminal of the switching circuit; the source of the fourth NMOS transistor N4 and the anode of its body diode are connected together to form the second input / output terminal of the switching circuit; the drain of the second NMOS transistor N3 and the cathode of its body diode, the drain of the fourth NMOS transistor N4 and the cathode of its body diode are connected together; the gates of the second NMOS transistor N3 and the fourth NMOS transistor N4, and the second terminal of the sixth resistor assembly 06 are all connected to the driving circuit 30 to receive the driving signal.

[0084] The sixth resistor assembly 06 includes the sixth resistor R6.

[0085] like Figure 7 and Figure 8 As shown, the driving circuit 30 includes a second field-effect transistor M2 and a second current-limiting resistor Rs2.

[0086] The gate of the second field-effect transistor M2 and the first end of the second current-limiting resistor Rs2 are connected and together form the input terminal of the drive circuit 30 to receive the control signal; the source of the second field-effect transistor M2 forms the output terminal of the drive circuit 30 and is connected to the gate of the first transistor 10 and the gate of the second transistor 20 to output the drive signal; the drain of the second field-effect transistor M2 is connected to the first power supply VAA; the second end of the second current-limiting resistor Rs2 is connected to the power supply ground.

[0087] Understandable Figure 7 and Figure 8 The transistor-based switching circuit shown utilizes its conduction characteristics to control the on / off state of the main circuit. Compared to PMOS, NMOS differs in principle and manufacturing process, resulting in NMOS being superior to PMOS in parameters such as turn-on speed, rated current, and on-resistance at the same price, as well as the turn-off and turn-on of the negative DC bus.

[0088] like Figure 7 and Figure 8 As shown, the first transistor 10 and the second transistor 20 are connected in series between the first node A and the second node B, wherein the first transistor 10 is connected to the first node A and the second transistor 20 is connected to the second node B; the transistor-based switching circuit also includes a second clamping circuit 120.

[0089] The second clamping circuit 120 is connected to the driving circuit 30, the first node A and the second node B, and is used to clamp the voltage between the first node A and the second node B according to the driving signal.

[0090] The second clamping circuit 120 includes a fifth PMOS transistor P5, a sixth PMOS transistor P6, a fifth NMOS transistor N5, a seventh PMOS transistor P7, and an eighth PMOS transistor P8;

[0091] The source and gate of the fifth PMOS transistor P5 are connected to the first power supply VAA. The drain of the fifth PMOS transistor P5 is connected to the source of the sixth PMOS transistor P6. The drain of the sixth PMOS transistor P6 is connected to the drain of the fifth NMOS transistor N5, the source of the seventh PMOS transistor P7, and the source of the eighth PMOS transistor P8. The gate of the sixth PMOS transistor P6, the gate of the fifth NMOS transistor N5, and the gate of the eighth PMOS transistor P8 together serve as the drive signal input terminal of the second clamping circuit 120 to input the drive signal. The drain of the eighth PMOS transistor P8 is connected to the first node A, and the gate of the seventh PMOS transistor P7 is connected to the second node B. The source of the fifth NMOS transistor N5 and the drain of the seventh PMOS transistor P7 are connected to the power supply ground.

[0092] exist Figures 5 to 8 In the first protection circuit 80, a first TVS transistor TVS1 is included, wherein the first end of the first TVS transistor TVS1 is connected to the drain of the first transistor 10, and the second end of the first TVS transistor TVS1 is connected to the source of the first transistor 10.

[0093] The second protection circuit 90 includes a second TVS transistor TVS2, wherein the first end of the second TVS transistor TVS2 is connected to the drain of the second transistor 20, and the second end of the second TVS transistor TVS2 is connected to the source of the second transistor 20.

[0094] The following is based on the working principle. Figures 5 to 8 Further explanation is provided below:

[0095] like Figure 5 and Figure 6 As shown, when a control signal (high level) is connected to the gate of the first field-effect transistor M1, the first field-effect transistor M1 is turned on, and a drive signal (low level) is output from the drain of the first field-effect transistor M1. Figure 5 As shown, when a low-level drive signal is applied to the gate of the first PMOS transistor P1 and the gate of the second PMOS transistor P2, both PMOS transistors P1 and P2 are turned on. Current can flow from the source of the first PMOS transistor P1 (the first input / output terminal of the switching circuit) to the source of the second PMOS transistor P2 (the second input / output terminal of the switching circuit), and vice versa. Figure 6As shown, when a low-level drive signal is applied to the gate of the third PMOS transistor P3 and the gate of the fourth PMOS transistor P4, the third PMOS transistor P3 and the fourth PMOS transistor P4 are turned on. Current can be output from the drain of the third PMOS transistor P3 (the first input / output terminal of the switching circuit) to the drain of the fourth PMOS transistor P4 (the second input / output terminal of the switching circuit), and current can also be output from the drain of the fourth PMOS transistor P2 (the second input / output terminal of the switching circuit) to the drain of the third PMOS transistor P3 (the first input / output terminal of the switching circuit).

[0096] Simultaneously, the gate of the ninth PMOS transistor P9 receives a low-level drive signal and is turned on. The source of the ninth PMOS transistor P9 is connected to the first power supply VDD. Therefore, the drain voltage of the ninth PMOS transistor P9 is VDD, the drain voltage of the eighth NMOS transistor N8 is VDD, and the drain-source voltage of the eighth NMOS transistor N8 is the drain-source voltage Vds of the ninth PMOS transistor P9. This is extremely small when the first and second transistors are normally turned on, so the leakage current of the eighth NMOS transistor N8 is extremely small, and thus the leakage current through the first clamping circuit is extremely small.

[0097] like Figure 5 and Figure 6 As shown, when the control signal is disconnected, the first field-effect transistor M1 is turned off, and the drain of the first field-effect transistor M1 stops outputting the drive signal (high level). Figure 5 As shown, when the gate of the first PMOS transistor P1 and the gate of the second PMOS transistor P2 are no longer connected to the drive signal, the first PMOS transistor P1 and the second PMOS transistor P2 are turned off. Since the body diodes of the first PMOS transistor P1 and the second PMOS transistor are connected relative to each other, the series-connected first PMOS transistor P1 and the second PMOS transistor P2 have a bidirectional cutoff function, thus reducing the possibility of leakage current. Figure 6 As shown, when the drive signal is stopped from being applied to the gates of the third PMOS transistor P3 and the fourth PMOS transistor P4, the third PMOS transistor P3 and the fourth PMOS transistor P4 are turned off. Since the body diodes of the third PMOS transistor P3 and the fourth PMOS transistor P4 are connected relative to each other, the series-connected third PMOS transistor P3 and the fourth PMOS transistor P4 have a bidirectional cutoff function, thus reducing the possibility of leakage current.

[0098] Simultaneously, the gate and source of the sixth NMOS transistor N6 are connected to the power supply ground GND, the gate of the eighth NMOS transistor N8 is connected to the second node B, and the drain of the eighth NMOS transistor N8 is connected to the first power supply VDD. The ninth NMOS transistor N9 and the seventh NMOS transistor N7 are turned on according to the disconnection (high level) of the drive signal, so the sixth NMOS transistor N6 and the eighth NMOS transistor N8 form a voltage follower, thereby clamping the voltage between the first node A and the second node B. The voltage difference between the first node A and the second node B is the gate-source voltage Vgs of the eighth NMOS transistor N8. Since the eighth NMOS transistor N8 is connected to the very small current generated by the sixth NMOS transistor N6, it can be seen that the Vgs of the eighth NMOS transistor N5 is very small, approximately equal to the threshold voltage Vth of the eighth NMOS transistor N5. Therefore, the sum of the drain-source voltage of the first transistor and the drain-source voltage of the second transistor is Vth. Since Vth is very small, the leakage current through the first transistor and the second transistor is also very small, thereby effectively reducing the leakage current through the switching circuit.

[0099] like Figure 7 and Figure 8 As shown, when the gate of the second field-effect transistor M2 is connected to a control signal (high level), the second field-effect transistor M2 is turned on, and the drain of the second field-effect transistor M2 outputs a drive signal (high level). Figure 7 As shown, when a high-level drive signal is applied to the gate of the first NMOS transistor N1 and the gate of the second NMOS transistor N2, both NMOS transistors N1 and N2 are turned on. Current can flow from the source of the first NMOS transistor N1 (the first input / output terminal of the switching circuit) to the source of the second NMOS transistor N2 (the second input / output terminal of the switching circuit), and vice versa. Figure 8 As shown, when a low-level drive signal is applied to the gate of the third NMOS transistor N3 and the gate of the fourth NMOS transistor N4, the third NMOS transistor N3 and the fourth NMOS transistor N4 are turned on. Current can be output from the drain of the third NMOS transistor N3 (the first input / output terminal of the switching circuit) to the drain of the fourth NMOS transistor N4 (the second input / output terminal of the switching circuit), and current can also be output from the drain of the fourth NMOS transistor N4 (the second input / output terminal of the switching circuit) to the drain of the third NMOS transistor N3 (the first input / output terminal of the switching circuit).

[0100] Simultaneously, the gate of the fifth NMOS transistor N5 receives a high-level drive signal and is turned on. The source of the fifth NMOS transistor N5 is connected to the power supply ground GND. Therefore, the drain voltage of the fifth NMOS transistor N5 is Vds, which is the source voltage of the seventh PMOS transistor P7. At the same time, the drain voltage of the seventh PMOS transistor P7 is GND. Since Vds is extremely small when the first and second transistors are normally turned on, the drain-source voltage of the seventh PMOS transistor P7 is extremely small, thereby suppressing the leakage current of the seventh PMOS transistor P7. As a result, the leakage current through the second clamping circuit is extremely small.

[0101] like Figure 7 and Figure 8 As shown, when the control signal is disconnected, the second field-effect transistor M2 is turned off, and the drain of the second field-effect transistor M2 stops outputting the drive signal (low level). Figure 7 As shown, when the gate of the first NMOS transistor N1 and the gate of the second NMOS transistor N2 are no longer connected to the drive signal, the first NMOS transistor N1 and the second NMOS transistor N2 are turned off. Since the body diodes of the first NMOS transistor N1 and the second NMOS transistor are connected relative to each other, the series-connected first NMOS transistor N1 and the second NMOS transistor N2 have a bidirectional cutoff function, thus reducing the possibility of leakage current. Figure 8 As shown, when the gates of the third NMOS transistor N3 and the fourth NMOS transistor N4 are deactivated by the drive signal, the third NMOS transistor N3 and the fourth NMOS transistor N4 are turned off. Since the body diodes of the third NMOS transistor N3 and the fourth NMOS transistor N4 are connected in a relative manner, the series-connected third NMOS transistor N3 and the fourth NMOS transistor N4 have a bidirectional cutoff function, thus reducing the possibility of leakage current.

[0102] Simultaneously, the gate and source of the fifth PMOS transistor P5 are connected to the first power supply VDD, the gate of the seventh PMOS transistor P7 is connected to the second node B, and the drain of the seventh PMOS transistor P7 is connected to the power supply ground GND. The sixth PMOS transistor P6 and the eighth PMOS transistor P8 are turned on according to the disconnection (low level) of the drive signal, so the fifth PMOS transistor P5 and the seventh PMOS transistor P7 form a voltage follower, thereby clamping the voltage between the first node A and the second node B. The voltage difference between the first node A and the second node B is the gate-source voltage Vgs of the seventh PMOS transistor P7. Since the seventh PMOS transistor P7 has a very small current generated by the fifth PMOS transistor P5 from the first power supply VDD, it can be seen that the Vgs of the seventh PMOS transistor P7 is very small, approximately equal to the threshold voltage Vth of the seventh PMOS transistor P7. Therefore, the sum of the drain-source voltage of the first transistor and the drain-source voltage of the second transistor is Vth. Since Vth is very small, the leakage current through the first transistor and the second transistor is also very small, thereby effectively reducing the leakage current through the switching circuit.

[0103] exist Figures 5 to 8 In the circuit, the first TVS diode (TVS1) breaks down and releases energy in response to a voltage greater than a preset voltage between the drain and source of the first transistor; the second TVS diode (TVS2) breaks down and releases energy in response to a voltage greater than a preset voltage between the drain and source of the second transistor. This invention also provides an electronic device including the aforementioned transistor-based switching circuit.

[0104] This invention includes a first transistor, a second transistor, and a driving circuit. The first and second transistors are connected in series, and the body diodes of the first and second transistors are connected opposite to each other. Resistive components are provided between the drain and gate of the first transistor and between the drain and gate of the second transistor. The driving circuit receives a control signal and outputs a driving signal according to the control signal to drive the first and second transistors to turn on. In response to the cessation of the control signal, the output of the driving signal is disconnected. The first and second transistors turn on according to the driving signal and turn off according to the disconnection of the driving signal. Therefore, when the driving signal is disconnected, the series-connected first and second transistors have a bidirectional cutoff function, reducing the possibility of leakage current.

[0105] It should be understood that the sequence number of each step in the above embodiments does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0106] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A transistor-based switching circuit, characterized in that, Includes a first transistor, a second transistor, and a driving circuit; The first transistor and the second transistor are connected in series, and the body diodes of the first transistor and the second transistor are connected opposite to each other. A resistor assembly is provided between the drain and gate of the first transistor and between the drain and gate of the second transistor. The driving circuit is connected to the resistor assembly, the gate of the first transistor, and the gate of the second transistor. It is used to receive a control signal and output a driving signal according to the control signal to drive the first transistor and the second transistor to turn on. In response to the stop of the control signal, the output of the driving signal is disconnected. The first transistor and the second transistor are configured to turn on according to the drive signal and turn off according to the disconnection of the drive signal.

2. The transistor-based switching circuit as described in claim 1, characterized in that, A first resistor assembly is disposed between the drain and the gate of the first transistor; a second resistor assembly is disposed between the drain and the gate of the second transistor. The first transistor is a first PMOS transistor, and the second transistor is a second PMOS transistor; The source of the first PMOS transistor, the cathode of the body diode of the first PMOS transistor, and the first end of the first resistor assembly are connected and together constitute the first input / output terminal of the switching circuit. The source of the second PMOS transistor, the cathode of the body diode of the second PMOS transistor, and the first end of the second resistor assembly are connected and together constitute the second input / output terminal of the switching circuit. The gate of the first PMOS transistor, the gate of the second PMOS transistor, the second terminal of the first resistor assembly, and the second terminal of the second resistor assembly are all connected to the driving circuit. The drain of the first PMOS transistor is connected to the anode of the body diode of the first PMOS transistor, the drain of the second PMOS transistor, and the anode of the body diode of the second PMOS transistor.

3. The transistor-based switching circuit as described in claim 1, characterized in that, A third resistor assembly is provided between the drain and gate of the first transistor and between the drain and gate of the second transistor. The first transistor is a third PMOS transistor, and the second transistor is a fourth PMOS transistor; The drain of the third PMOS transistor and the anode of the body diode of the third PMOS transistor are connected and together form the first input / output terminal of the switching circuit. The drain of the fourth PMOS transistor and the anode of the body diode of the fourth PMOS transistor are connected and together form the second input / output terminal of the switching circuit. The source of the third PMOS transistor is connected to the first terminal of the third resistor assembly, the negative terminal of the body diode of the third PMOS transistor, the source of the fourth PMOS transistor, and the negative terminal of the body diode of the fourth PMOS transistor. The gates of the third PMOS transistor, the fourth PMOS transistor, and the second terminal of the third resistor assembly are all connected to the driving circuit to receive the driving signal.

4. The transistor-based switching circuit as described in claim 1, characterized in that, The driving circuit includes a first field-effect transistor and a first current-limiting resistor; The gate of the first field-effect transistor and the first end of the first current-limiting resistor are connected and together form the input terminal of the driving circuit to receive the control signal; The drain of the first field-effect transistor forms the output terminal of the driving circuit, and is connected to the gate of the first transistor and the gate of the second transistor to output the driving signal; The source of the first field-effect transistor and the second terminal of the first current-limiting resistor are both connected to the power supply ground.

5. The transistor-based switching circuit as described in any one of claims 2 to 4, characterized in that, The first transistor and the second transistor are connected in series between the first node A and the second node B, wherein the first transistor is connected to the first node A and the second transistor is connected to the second node B; The transistor-based switching circuit also includes: A first clamping circuit, connected to the driving circuit, the first node A, and the second node B, is used to clamp the voltage between the first node A and the second node B according to the driving signal.

6. The transistor-based switching circuit as described in claim 5, characterized in that, The first clamping circuit includes a sixth NMOS transistor, a seventh NMOS transistor, a ninth PMOS transistor, an eighth NMOS transistor, and a ninth NMOS transistor; The source and gate of the sixth NMOS transistor are connected to the power supply ground, and the drain of the sixth NMOS transistor is connected to the source of the seventh NMOS transistor. The drain of the seventh NMOS transistor is connected to the drain of the ninth PMOS transistor, the source of the eighth NMOS transistor, and the source of the ninth NMOS transistor. The gates of the seventh NMOS transistor, the ninth PMOS transistor, and the ninth NMOS transistor together serve as the drive signal input terminal of the first clamping circuit to input the drive signal. The drain of the ninth NMOS transistor is connected to the first node, and the gates of the eighth NMOS transistor are respectively connected to the second node. The source and drain of the ninth PMOS transistor are connected to the first power supply.

7. The transistor-based switching circuit as described in claim 1, characterized in that, A fourth resistor assembly is disposed between the drain and the gate of the first transistor; a fifth resistor assembly is disposed between the drain and the gate of the second transistor. The first transistor is a first NMOS transistor, and the second transistor is a second NMOS transistor; The source of the first NMOS transistor, the cathode of the body diode of the first NMOS transistor, and the first end of the fourth resistor assembly are connected and together constitute the first input / output terminal of the switching circuit. The source of the second NMOS transistor, the cathode of the body diode of the second NMOS transistor, and the first terminal of the fifth resistor assembly are connected and together constitute the second input / output terminal of the switching circuit; The gates of the first NMOS transistor, the second NMOS transistor, the second terminal of the fourth resistor assembly, and the second terminal of the fifth resistor assembly are all connected to the driving circuit to receive the driving signal. The drain of the first NMOS transistor is connected to the anode of the body diode of the first NMOS transistor, the drain of the second NMOS transistor, and the anode of the body diode of the second NMOS transistor.

8. The transistor-based switching circuit as described in claim 1, characterized in that, A sixth resistor assembly is provided between the drain and gate of the first transistor and between the drain and gate of the second transistor. The first transistor is a third NMOS transistor, and the second transistors are both fourth NMOS transistors; The source of the third NMOS transistor and the positive terminal of the body diode of the third NMOS transistor are connected and together form the first input-output terminal of the switching circuit. The source of the fourth NMOS transistor and the anode of the body diode of the fourth NMOS transistor are connected and together form the second input-output terminal of the switching circuit. The drain of the third NMOS transistor is connected to the negative terminal of the body diode of the third NMOS transistor, the drain of the fourth NMOS transistor, and the negative terminal of the body diode of the fourth NMOS transistor. The gates of the third NMOS transistor, the fourth NMOS transistor, and the second terminal of the sixth resistor assembly are all connected to the driving circuit to receive the driving signal.

9. The transistor-based switching circuit as described in claim 1, characterized in that, The driving circuit includes a second field-effect transistor and a second current-limiting resistor; The gate of the second field-effect transistor and the first end of the second current-limiting resistor are connected and together form the input terminal of the driving circuit to receive the control signal; The source of the second field-effect transistor forms the output terminal of the driving circuit, and is connected to the gate of the first transistor and the gate of the second transistor to output the driving signal; The drain of the second field-effect transistor is connected to the first power supply; The second terminal of the second current-limiting resistor is connected to the power supply ground.

10. The transistor-based switching circuit according to any one of claims 7 to 9, characterized in that, The first transistor and the second transistor are connected in series between the first node A and the second node B, wherein the first transistor is connected to the first node A and the second transistor is connected to the second node B; The transistor-based switching circuit also includes: The second clamping circuit is connected to the driving circuit, the first node A and the second node B, and is used to clamp the voltage between the first node A and the second node B according to the driving signal.

11. The transistor-based switching circuit as described in claim 10, characterized in that, The second clamping circuit includes a fifth PMOS transistor, a sixth PMOS transistor, a fifth NMOS transistor, a seventh PMOS transistor, and an eighth PMOS transistor; The source and gate of the fifth PMOS transistor are connected to the first power supply, and the drain of the fifth PMOS transistor is connected to the source of the sixth PMOS transistor. The drain of the sixth PMOS transistor is connected to the drain of the fifth NMOS transistor, the source of the seventh PMOS transistor, and the source of the eighth PMOS transistor. The gates of the sixth PMOS transistor, the fifth NMOS transistor, and the eighth PMOS transistor serve as the drive signal input terminals of the second clamping circuit to input the drive signal. The drain of the eighth PMOS transistor is connected to the first node, and the gate of the seventh PMOS transistor is connected to the second node. The source and drain of the fifth NMOS transistor are connected to the power supply ground.

12. The transistor-based switching circuit as described in claim 1, characterized in that, Also includes: An energy storage circuit, connected to the second transistor, is used to output DC power for power supply; A load, connected to the first transistor, is used to operate according to the supplied DC power; The first transistor and the second transistor are used to transmit the DC power supply according to the drive signal.

13. The transistor-based switching circuit as described in claim 12, characterized in that, Also includes: A charging circuit, connected to the first transistor and the load, is used to output charging DC power; The energy storage circuit is also used to charge the device according to the charging DC power. The load is also used to operate according to the charging DC power; The first transistor and the second transistor are also used to transmit the charging DC power according to the drive signal.

14. The transistor-based switching circuit as described in claim 13, characterized in that, The first transistor and the second transistor are also configured to stop transmitting the charging DC power and the supply DC power in response to the disconnection of the drive signal.

15. An electronic device, characterized in that, The electronic device includes a transistor-based switching circuit as described in any one of claims 1 to 14.

Images