High-side switch system and control method thereof, chip and electronic equipment

Abstract

The invention discloses a high-side switch system, a control method thereof, a chip and electronic equipment, and relates to the technical field of electronic circuits. The high-side switching system comprises a first switching tube, a load, a power supply reverse connection protection circuit and an input voltage bus. The power supply reverse connection protection circuit is configured to input a first voltage to the third end of the power supply reverse connection protection circuit when the positive electrode of the power supply is connected with the first ground and the negative electrode of the power supply is connected with the input voltage bus. And a current path flowing from the third end of the power supply reverse connection protection circuit to the first end of the power supply reverse connection protection circuit is conducted in response to the first voltage, so that current is provided for the first end of the first switch tube through the current path to drive the first switch tube to be conducted. The power supply reverse connection protection circuit is further configured to disconnect the current path when the positive electrode of the power supply is connected with the input voltage bus and the negative electrode of the power supply is connected with the first ground. In this way, the risk that the high-side switch is damaged can be reduced.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of electronic circuit technology, and in particular to a high-side switch system and a control method thereof, a chip and an electronic device. Background Art

[0002] For devices equipped with chips (such as vehicle-mounted chips), a common problem in practical applications is that when a user reverses the polarity of a power source due to improper use, the electronic components in the device may be damaged.

[0003] Among them, for a chip with a high-side switch, when the chip is connected to a load, the source of the high-side switch is connected to the load, and the drain of the high-side switch is connected to the input voltage bus. When the power supply is reversed, the current will be injected from the positive pole of the power supply to the ground, and flow through the load and the body diode of the high-side switch to the input voltage bus to flow into the negative pole of the power supply, thereby forming a path. However, since the internal resistance of the load can be very small, and the body diode of the high-side switch will generate at least a 0.7V voltage drop when it is turned on, the power loss on the body diode of the high-side switch can be very large, and excessive power loss will cause the high-side switch to overheat and be damaged. Summary of the invention

[0004] The embodiments of the present application provide a high-side switch system and a control method thereof, a chip and an electronic device, which can reduce the risk of damage to the high-side switch.

[0005] In a first aspect, an embodiment of the present application provides a high-side switch system, including:

[0006] The first switch tube, the load, the power reverse connection protection circuit and the input voltage bus;

[0007] The first end of the first switch tube is connected to the first end of the power reverse connection protection circuit, the second end of the first switch tube and the first end of the load are connected to the voltage output end of the high-side switch system, the third end of the first switch tube and the second end of the power reverse connection protection circuit are both connected to the input voltage bus, and the second end of the load is connected to the first ground;

[0008] The power reverse connection protection circuit is configured such that when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, a first voltage is input to the third terminal of the power reverse connection protection circuit, and in response to the first voltage, a current path flowing from the third terminal of the power reverse connection protection circuit to the first terminal of the power reverse connection protection circuit is turned on, and then a current is provided to the first terminal of the first switch tube through the current path to drive the first switch tube to turn on;

[0009] The power reverse connection protection circuit is further configured to disconnect the current path when the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground.

[0010] In one or more embodiments, the third terminal of the power supply reverse connection protection circuit is connected to the first ground, wherein when the positive pole of the power supply is connected to the first ground and the negative pole of the power supply is connected to the input voltage bus, the first voltage is equal to the voltage of the power supply.

[0011] In one or more embodiments, the high-side switch system further includes an external circuit, a first end of the external circuit is connected to a third end of the power reverse connection protection circuit, and a second end of the external circuit is connected to the first ground;

[0012] The external circuit is configured to output the first voltage to the third terminal of the power reverse connection protection circuit based on the voltage of the power supply when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus.

[0013] In one or more embodiments, the external circuit includes a first diode, an anode of the first diode is connected to the first ground, and a cathode of the first diode is connected to a first end of the external circuit;

[0014] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the difference between the voltage of the power supply and the conduction voltage drop of the first diode.

[0015] In one or more embodiments, the power reverse connection protection circuit includes a second switch tube, a first Zener diode, a second diode and a first resistor;

[0016] The first resistor is connected between the anode of the second diode and the first ground, the cathode of the second diode is respectively connected to the cathode of the first Zener diode and the second end of the second switch tube, the first end of the second switch tube and the anode of the first Zener diode are both connected to the input voltage bus, and the third end of the second switch tube is connected to the first end of the power reverse protection circuit.

[0017] In one or more embodiments, the power reverse connection protection circuit further includes a third switch tube and a third diode provided between the cathode of the first Zener diode and the second end of the second switch tube, wherein the second diode is a body diode of the third switch tube;

[0018] The first end of the third switch tube is connected to the input voltage bus, the second end of the third switch tube is connected to the cathode of the first Zener diode and the anode of the third diode, the third end of the third switch tube is connected to the first resistor, and the cathode of the third diode is connected to the second end of the second switch tube.

[0019] In one or more embodiments, the first switch tube and the power reverse connection protection circuit are integrated into a same chip, and the substrate of the chip is the second ground.

[0020] In one or more embodiments, the high-side switch system further includes a first Schottky diode;

[0021] An anode of the first Schottky diode is connected to a voltage output terminal of the high-side switch system, and a cathode of the first Schottky diode is connected to the input voltage bus.

[0022] In one or more embodiments, the high-side switch system further includes a second Schottky diode;

[0023] An anode of the second Schottky diode is connected to the second ground, and a cathode of the second Schottky diode is connected to the input voltage bus.

[0024] In one or more embodiments, the high-side switch system further comprises a switch circuit, wherein the switch circuit is connected between the input voltage bus and the second ground;

[0025] The switch circuit is configured to be turned on when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, so as to short-circuit the input voltage bus and the second ground;

[0026] The switch circuit is further configured to be disconnected when the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground, so as to stop short-circuiting the input voltage bus and the second ground.

[0027] In one or more embodiments, the switch circuit includes a fourth switch tube;

[0028] The first end of the fourth switch tube is connected to the third end of the power reverse connection protection circuit, the third end of the fourth switch tube is connected to the input voltage bus, and the second end of the fourth switch tube is connected to the second ground.

[0029] In one or more embodiments, the switch circuit further includes a second Zener diode, a third resistor, and a fourth resistor;

[0030] The anode of the second Zener diode and the first end of the third resistor are both connected to the second ground, the cathode of the second Zener diode is respectively connected to the second end of the third resistor, the first end of the fourth resistor and the first end of the fourth switch tube, and the second end of the fourth resistor is connected to the third end of the power reverse protection circuit.

[0031] In one or more embodiments, the switch circuit further includes a fifth switch tube, a sixth switch tube, a third Zener diode, a fifth resistor, a sixth resistor and a seventh resistor;

[0032] The third end of the fifth switch tube is connected to the first end of the fourth resistor and the first end of the fourth switch tube respectively, the second end of the fifth switch tube, the first end of the fifth resistor and the anode of the third Zener diode are all connected to the second ground, the cathode of the third Zener diode is connected to the second end of the fifth resistor, the second end of the sixth switch tube and the first end of the fifth switch tube respectively, the first end of the sixth switch tube is connected to the second end of the fourth resistor and the second end of the seventh resistor respectively, the third end of the sixth switch tube is connected to the second end of the sixth resistor, the first end of the seventh resistor is connected to the third end of the power reverse protection circuit, and the first end of the sixth resistor is connected to the input voltage bus.

[0033] In one or more embodiments, the high-side switch system also includes a grounding network, a first end of the grounding network is connected to the first ground, and a second end of the grounding network is connected to the second ground, wherein the grounding network includes a fourth diode and an eighth resistor, a cathode of the fourth diode and a first end of the eighth resistor are both connected to the first end of the grounding network, and an anode of the fourth diode and a second end of the eighth resistor are both connected to the second end of the grounding network.

[0034] In a second aspect, an embodiment of the present application provides a control method for a high-side switch system, wherein the high-side switch system includes a first switch tube connected between an input voltage bus and a voltage output end of the high-side switch system, a load connected between the voltage output end of the high-side switch system and a first ground, and a power reverse connection protection circuit, wherein a first end of the power reverse connection protection circuit is connected to a first end of the first switch tube, and a second end of the power reverse connection protection circuit is connected to the input voltage bus, and the method includes:

[0035] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the third terminal of the power supply reverse connection protection circuit is configured to input a first voltage to conduct a current path for current to flow from the third terminal of the power supply reverse connection protection circuit to the first terminal of the power supply reverse connection protection circuit, wherein the current path provides current to the first terminal of the first switch tube to drive the first switch tube to conduct;

[0036] When the positive electrode of the power source is connected to the input voltage bus and the negative electrode of the power source is connected to the first ground, the current path is disconnected.

[0037] In one or more embodiments, the third terminal of the power reverse connection protection circuit is connected to the first ground;

[0038] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the voltage of the power supply.

[0039] In one or more embodiments, the high-side switch system further comprises an external circuit, wherein a first end of the external circuit is connected to a third end of the power reverse connection protection circuit, a second end of the external circuit is connected to the first ground, and the external circuit comprises a first diode, wherein an anode of the first diode is connected to the first ground, and a cathode of the first diode is connected to the first end of the external circuit;

[0040] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the difference between the voltage of the power supply and the conduction voltage drop of the first diode.

[0041] In one or more embodiments, the first switch and the power reverse connection protection circuit are integrated into the same chip, the substrate of the chip is the second ground, the high-side switch system further includes a grounding network and a switch circuit, the grounding network is connected between the first ground and the second ground, the switch circuit is connected between the input voltage bus and the second ground, wherein the grounding network includes a fourth diode and an eighth resistor, the cathode of the fourth diode and the first end of the eighth resistor are both connected to the first ground, the anode of the fourth diode and the second end of the eighth resistor are both connected to the second ground, and the method further includes:

[0042] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, turning on the switch circuit to short-circuit the input voltage bus and the second ground;

[0043] When the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground, the switch circuit is disconnected.

[0044] In a third aspect, an embodiment of the present application provides a chip, including the first switch tube and the power reverse connection protection circuit in the high-side switch system as described above.

[0045] In a fourth aspect, an embodiment of the present application provides an electronic device, comprising the chip as described above.

[0046] The beneficial effect of the present application is that the high-side switch system of the embodiment of the present application includes a first switch tube, a load, a power reverse connection protection circuit and an input voltage bus. When the positive pole of the power supply is connected to the first ground and the negative pole of the power supply is connected to the input voltage bus, that is, when the power supply is reversed, the third end of the power reverse connection protection circuit inputs the first voltage, and in response to the first voltage, the current path flowing from the third end of the power reverse connection protection circuit to the first end of the power reverse connection protection circuit is turned on, and then the current is provided to the first end of the first switch tube through the current path to drive the first switch tube to turn on. In this way, the reverse current from the first ground to the input voltage bus will not pass through the body diode of the first switch tube, but mainly flows through the first switch tube in the on state. Since the equivalent resistance of the first switch tube is very small when it is turned on, the heat generated on the first switch tube when carrying the reverse current is very small, which can protect the first switch tube when the power supply is reversed, which is conducive to reducing the risk of damage to the first switch tube (corresponding to the high-side switch). Secondly, when the positive pole of the power supply is connected to the input voltage bus and the negative pole of the power supply is connected to the first ground, that is, when the power supply is positively connected, the power reverse connection protection circuit can also disconnect the current path, thereby not affecting the normal operation of the first switch tube. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] One or more embodiments are exemplarily described by the figures in the corresponding drawings, and these exemplary descriptions are not intended to limit the embodiments. Elements with the same reference numerals in the drawings represent similar elements.

[0048] Figure 1 is a schematic diagram of the composition structure of the high-side switch system provided in the embodiment of the present application Figure 1 ;

[0049] Figure 2 is a schematic diagram of the composition structure of the high-side switch system provided in the embodiment of the present application Figure 2 ;

[0050] Figure 3 is a schematic diagram of the composition structure of the high-side switch system provided in the embodiment of the present application Figure 3 ;

[0051] Figure 4is a schematic diagram of the composition structure of the high-side switch system provided in the embodiment of the present application Figure 4 ;

[0052] Figure 5 is a schematic diagram of the composition structure of the high-side switch system provided in the embodiment of the present application Figure 5 ;

[0053] Figure 6 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 1 ;

[0054] Figure 7 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 2 ;

[0055] Figure 8 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 3 ;

[0056] Fig. 9 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 4 ;

[0057] Fig.10 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 5 ;

[0058] Fig.11 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 6 ;

[0059] Fig.12 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 7 ;

[0060] Fig.13 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 8 ;

[0061] Fig.14 The circuit structure of the high side switch system provided in the embodiment of the present application is shown in FIG. Figure 9 ;

[0062] Fig.15 4 is a flow chart of a control method of a high-side switch system provided in an embodiment of the present application. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and in detail in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0064] It should be noted that, when an element is described as being “connected to” another element, it may be directly connected to the other element, or one or more intervening elements may exist therebetween.

[0065] In addition, the technical features involved in the various embodiments of the present application described below can be combined with each other as long as there is no structural conflict between them.

[0066] Please refer to Figure 1 , Figure 1 Schematic diagram of the composition structure of the high-side switch system provided in the embodiment of the present application. Figure 1 As shown, the high-side switch system 100 includes a first switch tube Q1, a load 20, a power reverse connection protection circuit 10 and an input voltage bus VBB. It can be understood that in the embodiment of the present application, the first switch tube Q1 corresponds to a high-side switch.

[0067] Among them, the first end of the first switch tube Q1 is connected to the first end S1 of the power reverse connection protection circuit 10; the second end of the first switch tube Q1 and the first end of the load 20 are connected to the voltage output end VOUT of the high-side switch system 100; the third end of the first switch tube Q1 and the second end S2 of the power reverse connection protection circuit 10 are both connected to the input voltage bus VBB; the second end of the load 20 is connected to the first ground SGND.

[0068] Specifically, when the positive electrode of the power supply is connected to the first ground SGND and the negative electrode of the power supply is connected to the input voltage bus VBB, that is, when the power supply is reversed, the third terminal S3 of the power supply reverse connection protection circuit 10 inputs the first voltage, and at the same time, the power supply reverse connection protection circuit 10 conducts the current path from the third terminal S3 of the power supply reverse connection protection circuit 10 to the first terminal S1 of the power supply reverse connection protection circuit 10 in response to the first voltage, and then provides current to the first terminal of the first switch tube Q1 through the current path to drive the first switch tube Q1 to turn on. In this way, the current from the first ground SGND to the input voltage bus VBB (referred to as reverse current) will not pass through the body diode of the first switch tube Q1, but mainly flows through the first switch tube Q1 in the on state. Since the equivalent resistance of the first switch tube Q1 is very small when it is turned on, the heat generated on the first switch tube Q1 when carrying the reverse current is very small, which can protect the first switch tube Q1 when the power supply is reversed, which is conducive to reducing the risk of damage to the first switch tube Q1 (i.e., the high-side switch).

[0069] In the related art, since the power reverse connection protection circuit 10 is not provided, when the power is reversed, the reverse current will flow through the body diode of the first switch tube Q1. Since the internal resistance of the load can be very small, and the body diode of the first switch tube Q1 will generate at least a 0.7V voltage drop when it is turned on, the power loss on the body diode of the first switch tube Q1 can be very large, and excessive power loss will cause the first switch tube Q1 to overheat and be damaged. It can be seen that compared with the related art, the embodiment of the present application can reduce the risk of damage to the first switch tube Q1 to a large extent by adding the power reverse connection protection circuit 10.

[0070] The power source is a device that provides electrical energy. In one embodiment, the power source is a battery.

[0071] In addition, in an embodiment of the present application, when the positive electrode of the power supply is connected to the input voltage bus VBB and the negative electrode of the power supply is connected to the first ground SGND, that is, when the power supply is positively connected, the power reverse connection protection circuit 10 can also disconnect the current path, that is, disconnect the current path between the third terminal S3 of the power reverse connection protection circuit 10 and the first terminal S1 of the power reverse connection protection circuit 10, so that when the power supply is positively connected, the power reverse connection protection circuit 10 will not affect the normal operation of the first switch tube Q1, that is, the first switch tube Q1 can normally perform its corresponding function.

[0072] It should be noted that, in the embodiments of the present application, taking the case where each switch tube (such as the first switch tube Q1) is a MOS tube, the first end of each switch tube is the gate of the MOS tube, the second end of each switch tube is the source of the MOS tube, and the third end of each switch tube is the drain of the MOS tube.

[0073] In addition, each switch tube can be any controllable switch, such as an insulated gate bipolar transistor (IGBT) device, an integrated gate commutated thyristor (IGCT) device, a gate turn-off thyristor (GTO) device, a silicon controlled rectifier (SCR) device, a junction gate field effect transistor (JFET) device, a MOS controlled thyristor (MCT) device, etc.

[0074] In some embodiments, the first voltage is linearly related to the voltage of the power supply.

[0075] Specifically, when the positive electrode of the power supply is connected to the first ground SGND and the negative electrode of the power supply is connected to the input voltage bus VBB, a first voltage is generated based on the voltage of the power supply and is linearly related to the first voltage. For example, the voltage of the power supply is in direct proportion to the first voltage. In some embodiments, the first voltage is equal to the voltage of the power supply, that is, there is a direct proportional relationship between the two with a ratio of 1. In other embodiments, the first voltage is obtained by subtracting a preset threshold from the voltage of the power supply, that is, there is a linear relationship between the two with a ratio of 1 and a difference of the preset threshold.

[0076] In some embodiments, Figure 2 As shown, the third terminal of the power reverse connection protection circuit 100 is connected to the first ground SGND, wherein when the positive electrode of the power supply is connected to the first ground SGND and the negative electrode of the power supply is connected to the input voltage bus VBB, the first voltage is equal to the voltage of the power supply.

[0077] When the power supply is reversely connected, due to the clamping effect of the body diode Db of the first switch tube Q1, the voltage at the voltage output terminal VOUT is higher than the voltage of the input voltage bus VBB by a forward conduction voltage drop of a body diode (about 0.7V). At this time, by establishing a current path from the third terminal S3 of the power supply reverse connection protection circuit 10 to the first terminal S1, the voltage on the positive electrode of the power supply connected to the first ground SGND can be converted into a voltage for controlling the gate of the first switch tube Q1, so that the voltage difference between it and the voltage output terminal VOUT exceeds the conduction threshold voltage of the first switch tube Q1, so that the first switch tube Q1 is turned on. Thereby, the purpose of protecting the first switch tube Q1 is achieved.

[0078] In one embodiment, if Figure 3 As shown, the high-side switch system further includes an external circuit 30. A first end of the external circuit 30 is connected to the third end S3 of the power reverse connection protection circuit 10, and a second end of the external circuit 30 is connected to the first ground SGND.

[0079] Specifically, when the positive pole of the power supply is connected to the first ground SGND and the negative pole of the power supply is connected to the input voltage bus VBB, that is, when the power supply is reversed, the external circuit 30 can output a first voltage to the third terminal S3 of the power reverse protection circuit 10 based on the voltage of the power supply to form a current path to drive the first switch tube Q1 to turn on.

[0080] When the positive pole of the power supply is connected to the input voltage bus VBB and the negative pole of the power supply is connected to the first ground SGND, that is, when the power supply is positively connected, the current path is disconnected, so that the voltage that the external circuit 30 may apply to the third terminal S3 of the power reverse connection protection circuit 10 will not affect the normal operation of the first switch tube Q1, that is, the first switch tube Q1 can perform its corresponding function normally.

[0081] In some embodiments, Figure 4 As shown, the external circuit 30 includes a first diode D1 . An anode of the first diode D1 is connected to the first ground SGND, and a cathode of the first diode D1 is connected to a first end of the external circuit 30 .

[0082] When the positive electrode of the power supply is connected to the first ground SGND and the negative electrode of the power supply is connected to the input voltage bus VBB, the first voltage is equal to the difference between the voltage of the power supply and the conduction voltage drop of the first diode D1.

[0083] In some embodiments, Figure 5 As shown, the high-side switch system 100 further includes a power supply protection branch 31. The power supply protection branch 31 is connected to the first node CEN with the third terminal S3 of the power reverse connection protection branch 10 and the cathode of the first diode D1. The power supply protection branch 31 is configured to remain off when the power supply is reversely connected to isolate the first node CEN and the input voltage bus VBB.

[0084] Specifically, in this embodiment, the external circuit 30 is configured as a controller for controlling the first switch tube Q1, such as a microcontroller (MCU). And the controller has the following three characteristics: first, the controller is connected between the input voltage bus VBB and the first ground SGND; second, the controller controls the first switch tube Q1 through the high and low levels at the first node CEN. For example, in some embodiments, the high level (such as the level corresponding to 5V) can be used to control the first switch tube Q1 to be enabled, and the low level (such as the level corresponding to 0V) can be used to control the first switch tube Q1 to be disconnected; third, between the first end and the second end of the external circuit 30, a first diode D1 for ESD protection is included. This makes it possible that when the power supply is reversed, the first node CEN in the external circuit 30 will have a voltage that is one diode forward conduction voltage drop lower than the voltage of the positive electrode of the power supply. This voltage can be used to control the power supply reverse connection protection circuit 10 to turn on the current path from the third end S3 of the power supply reverse connection protection circuit 10 to the first end S1, thereby controlling the first switch tube Q1 to be turned on to achieve protection of the first switch tube Q1.

[0085] Please refer to Figure 6 , Figure 6 An example is shown with Figure 1 A circuit structure corresponding to the composition structure shown. Figure 6 As shown, the power reverse connection protection circuit 10 includes a second switch tube Q2, a first Zener diode DW1, a second diode D2 and a first resistor R1.

[0086] Among them, the first resistor R1 is connected between the anode of the second diode D1 and the first ground SGND; the cathode of the second diode D2 is respectively connected to the cathode of the first Zener diode DW1 and the second end of the second switch tube Q2; the first end of the second switch tube Q2 and the anode of the first Zener diode DW1 are both connected to the input voltage bus VBB; the third end of the second switch tube Q2 is connected to the first end S1 of the power reverse protection circuit 10.

[0087] In this embodiment, the high side switch system 100 further includes a first current source I1 , a second current source I2 , a fourth Zener diode Z1 , a fifth diode Z2 , and a ninth resistor RA1 .

[0088] The anode of the fourth Zener diode Z1, the positive electrode of the first current source I1, and the negative electrode of the second current source I2 are all connected to the gate of the first switch tube Q1; the positive electrode of the second current source I2 is connected to the voltage output terminal VOUT; the first current source I1 charges the gate of the first switch tube Q1 with the current Ic in response to the first logic level of the enable signal EN, so as to turn on the first switch tube Q1; the second current source I2 charges the gate of the first switch tube Q1 with the current Ic in response to the first logic level of the enable signal EN, so as to turn on the first switch tube Q1;

[0089] —in response to the first logic level of the inverted signal EN (it can also be the second current source I2 in response to the second logic level of the enable signal) to discharge the gate of the first switch tube Q1 with the current Id to turn off the first switch tube Q1. The cathode of the fourth Zener diode Z1 is connected to the input voltage bus VBB. The ninth resistor RA1 is connected between the gate of the first switch tube Q1 and the voltage output terminal VOUT. The negative electrode of the first current source I1 is connected to the bias voltage VCP. Among them, the bias voltage VCP is generated by the voltage of the input voltage bus VBB through the bootstrap circuit, and is kept higher than the voltage of the input voltage bus VBB by at least one turn-on threshold voltage of the first switch tube Q1.

[0090] Specifically, the first current source I1 is responsible for providing a pull-up current to the first switch tube Q1 when the first switch tube Q1 is working normally, so that the first switch tube Q1 is turned on. The second current source I2 is responsible for providing a pull-down current to the first switch tube Q1 when the first switch tube Q1 is working normally, so that the first switch tube Q11 is turned off. The ninth resistor RA1 is a pull-down resistor. The clamping circuit composed of the fourth Zener diode Z1 and the fifth diode Z2 is used to clamp the voltage difference between the gate and the drain of the first switch tube Q1 to protect the first switch tube Q1.

[0091] When the power supply is reversed, that is, the negative electrode of the power supply is connected to the input voltage bus VBB, and the positive electrode of the power supply is connected to the first ground SGND. The first voltage is input to the third terminal S3 of the power supply reverse connection protection circuit 10. At this time, the first voltage is applied to the path composed of the first resistor R1, the second diode D2 and the first Zener diode DW1. The second diode D2 is forward-conducted, and the first Zener diode DW1 clamps the voltage between the source and the gate applied to the second switch tube Q2. In response to the source-gate voltage (that is, the voltage difference between the source and the gate) applied to the second switch tube Q2, the second switch tube Q2 is turned on, and the current path from the third terminal S3 of the power supply reverse connection protection circuit 10 to the first terminal S1 is correspondingly turned on. The voltage on the first ground SGND is applied to the gate of the first switch tube Q1 through the first resistor R1, the second diode D2 and the second switch tube Q2 part. At this time, due to the clamping effect of the body diode of the first switch tube Q1, the voltage of the source of the first switch tube Q1 (i.e., the voltage output terminal VOUT) is the voltage on the input voltage bus VBB plus the forward conduction voltage drop of a body diode (about 0.7V). Therefore, the clamping voltage of the first Zener diode DW1 can be set high enough so that the gate-source voltage of the first switch tube Q1 is sufficient to turn on the first switch tube Q1, so as to realize the shunting of the current on the body diode, thereby reducing the heat of the first switch tube Q1 and realizing the protection of the first switch tube Q1.

[0092] It is understood that in this application Figure 6 In the subsequent circuit structure, if the third terminal S3 of the power reverse connection protection circuit 10 can be as follows Figure 2 Connect to the first ground GND as shown, or Figure 4 When the third terminal S3 of the power reverse connection protection circuit 10 is connected to the first ground GND, the first voltage is the voltage difference between the first ground SGND and the input voltage bus VBB (i.e., the voltage of the power supply); when the third terminal S3 of the power reverse connection protection circuit 10 is connected to the first ground GND, the first voltage is the voltage difference between the first ground SGND and the input voltage bus VBB (i.e., the voltage of the power supply); Figure 4 When connected to the cathode of the first diode D1, the first voltage is the voltage difference between the first ground SGND and the input voltage bus VBB (ie, the voltage of the power supply) minus the forward conduction voltage drop of the first diode D1.

[0093] When the power supply is positively connected, that is, the positive electrode of the power supply is connected to the input voltage bus VBB, and the negative electrode of the power supply is connected to the first ground SGND, it is necessary to analyze it in two cases. In the first case, the first switch tube Q1 has been driven to turn on by the first current source I1, and the gate voltage of the first switch tube Q1 is the bias voltage VCP, which is greater than the voltage of the input voltage bus VBB plus the threshold voltage of at least one first switch tube Q1 (wherein the threshold voltage refers to a minimum value that the gate voltage needs to reach relative to the source voltage to form a channel and allow current to flow from the source to the drain, and this voltage is also called the threshold voltage). At this time, the source voltage of the second switch tube Q2 is greater than the gate voltage, and the second switch tube Q2 is turned on. However, since the first ground SGND is connected to the negative electrode of the power supply, the second diode D2 is reversely cut off, thereby shutting off the current path from the first terminal S1 to the third terminal S3 of the power reverse connection protection circuit 10. In the second case, the first switch tube Q1 has been driven to be turned off by the second current source I2, then the gate voltage of the first switch tube Q1 is the voltage of the voltage output terminal VOUT, and the second switch tube Q2 is turned off, which also cuts off the current path from the third terminal S3 of the power reverse connection protection circuit 10 to the first terminal S1.

[0094] In summary, Figure 6 The high-side switch system shown achieves that when the power supply is reversely connected, the first switch tube Q1 is controlled to be turned on to prevent the first switch tube Q1 from being damaged due to overheating. At the same time, when the power supply is positively connected, the normal operation of the first switch tube Q1 is not affected, that is, the first switch tube Q1 is not affected to be turned on by the first current source I1 and to be turned off by the second current source I2.

[0095] It should be noted that, in the embodiment of the present application, the voltage output terminal VOUT is connected to an inductive load (the inductive load is equivalent to a resistor RL and an inductor LL) as an example. In other embodiments, the voltage output terminal VOUT may also be connected to other types of loads, and the embodiment of the present application does not specifically limit this.

[0096] In one embodiment, if Figure 7 As shown, the power reverse connection protection circuit 100 further includes a third switch tube Q3 and a third diode D3 disposed between the cathode of the first Zener diode DW1 and the second end of the second switch tube Q2, wherein the second diode D2 is a body diode of the third switch tube Q3. Figure 6 The circuit structure shown in the figure is based on the example of adding a third switch tube Q3 and a third diode D3.

[0097] Specifically, a first end of the third switch tube Q3 is connected to the input voltage bus VBB; a second end of the third switch tube Q3 is connected to the cathode of the first Zener diode DW1 and the anode of the third diode D3; a third end of the third switch tube Q3 is connected to the first resistor R1; and a cathode of the third diode D3 is connected to the second end of the second switch tube Q2.

[0098] In this embodiment, the second diode D2 is implemented by the body diode of the third switch tube Q3. When the power supply is positively connected and the first switch tube Q1 is driven to be turned on by the first current source, the third diode D3 needs to be added to prevent the gate voltage (i.e., the bias voltage VCP) of the first switch tube Q1 from being reversely fed from the first terminal S1 of the power reverse connection protection circuit 10 through the body diode of the turned-on second switch tube Q2 and the turned-on third switch tube Q3 to the third terminal S3 of the power reverse connection protection circuit 10.

[0099] In some embodiments, the first switch tube Q1 and the power reverse connection protection circuit 10 are integrated into the same chip, and the substrate of the chip serves as the second ground.

[0100] Furthermore, in this embodiment, there is a parasitic resistor between the second ground and the voltage output terminal VOUT, and there is a parasitic diode between the input voltage bus VBB and the second ground.

[0101] like Figure 8 As shown, the resistor RB1 is a parasitic resistor between the second ground CGND and the voltage output terminal VOUT. Due to the existence of the resistor RB1, the second ground CGND and the voltage output terminal VOUT can be regarded as an approximately open circuit. The diode DA1 is a parasitic diode between the input voltage bus VBB and the second ground CGND.

[0102] Among them, the diode DA1 represents the parasitic PN junction between the N-type isolation ring (Isolation Ring) and the P-type substrate (P-SUB) in the chip. Among them, most of the N-type isolation rings are connected to the high level in the chip, that is, the input voltage bus VBB. Such a configuration will generate a small current from the second ground CGND to the input voltage bus VBB through the forward-conducting diode DA1 when the power supply is reversed. However, the device in the power supply reverse connection protection circuit 10, such as the second switch tube Q2, includes an N-type doped region in the structure, which can form a parasitic NPN transistor with the diode DA1 (the N-type isolation ring is the emitter, the P-type substrate is the base, and the N-type doped region is the collector). When the diode DA1 is turned on, the emitter junction of the parasitic NPN transistor is turned on, which will cause a large current to flow from the collector to the emitter, that is, from the N-type doped region in the structure of the second switch tube Q2 to the input voltage bus VBB. Since the N-type doped region of the second switch tube Q2 is the source of the second switch tube Q2 and is located between the first terminal S1 and the third terminal S3 of the power reverse connection protection circuit 10, the current flowing from the N-type doped region of the second switch tube Q2 to the input voltage bus VBB will shunt the current flowing from the third terminal S3 of the power reverse connection protection circuit 10 to the first terminal S1, and generate a significant voltage drop on the first resistor R1, so that the voltage transmitted to the gate of the first switch tube Q1 through the second switch tube Q2 is not enough to turn on the first switch tube Q1. In short, when the current flowing through the body diode of the first switch tube Q1 increases, the current flowing through the diode DA1 also increases with the voltage of the first ground CGND, thereby causing more current to be drawn from the gate of the first switch tube Q1, causing the first switch tube Q1 to be unable to turn on when the power is reversed.

[0103] The present application provides three solutions. The first solution is as follows: Figure 8 As shown, the high-side switch system 100 further includes a first Schottky diode DS1. Figure 6 The circuit structure shown is based on the example of adding the first Schottky diode DS1.

[0104] The anode of the first Schottky diode DS1 is connected to the voltage output terminal VOUT of the high-side switch system 100 , and the cathode of the first Schottky diode DS1 is connected to the input voltage bus VBB.

[0105] Specifically, since the forward conduction voltage of the first Schottky diode DS1 is lower than the forward conduction voltage of the diode DA1, more current flows from the voltage output terminal VOUT into the input voltage bus VBB through the first Schottky diode DS1, reducing the current injected into the N-type isolation ring of the first switch tube Q1, and will not cause an increase in the current on the diode DA1, and will not cause the current to be drawn away from the gate of the first switch tube Q1, so that the first switch tube Q1 can be turned on when the power supply is reversed.

[0106] The second solution is Fig. 9 As shown, the high-side switch system 100 further includes a second Schottky diode DS2. Figure 6 The circuit structure shown is based on the example of adding a second Schottky diode DS2.

[0107] The anode of the second Schottky diode DS2 is connected to the second ground CGND, and the cathode of the second Schottky diode DS2 is connected to the input voltage bus VBB.

[0108] Specifically, since the forward conduction voltage of the second Schottky diode DS2 is about 0.3V, which is lower than the forward conduction voltage of the diode DA1, when the power supply is reversely connected, the second Schottky diode DS2 is turned on before the diode DA1, and most of the current flows to the input voltage bus VBB through the second Schottky diode DS2. In this way, the conduction of the parasitic NPN transistor composed of the input voltage bus VBB, the second ground CGND and the source of the second switch tube Q2 is effectively prevented, so that the first switch tube Q1 can be turned on smoothly. Secondly, when the power supply is positively connected, the second Schottky diode DS2 remains reverse biased and does not affect the circuit function of the high-side switch system 100.

[0109] The third solution is Fig.10 As shown, the high-side switch system 100 further includes a switch circuit 40, and the switch circuit 40 is connected between the input voltage bus VBB and the second ground CGND. Figure 6 The circuit structure shown in the figure is based on the example of adding a switch circuit 40.

[0110] The switch circuit 40 is configured to be turned on when the positive electrode of the power supply is connected to the first ground SGND and the negative electrode of the power supply is connected to the input voltage bus VBB, so as to short-circuit the input voltage bus VBB and the second ground CGND. Thus, it is possible to prevent the current from flowing through the diode DA1, thereby preventing the parasitic NPN transistor composed of the input voltage bus VBB, the second ground CGND and the source of the second switch tube Q2 from being turned on, thereby ensuring that the first switch tube Q1 can be turned on smoothly when the power supply is reversely connected.

[0111] The switch circuit 40 is also configured to be disconnected when the positive electrode of the power supply is connected to the input voltage bus VBB and the negative electrode of the power supply is connected to the first ground SGND to stop short-circuiting the input voltage bus VBB and the second ground CGND, thereby not affecting the circuit function of the high-side switch system 100 .

[0112] In one embodiment, if Fig.11 As shown, the switch circuit 40 includes a fourth switch tube Q4.

[0113] The first end of the fourth switch tube Q4 is connected to the third end S3 of the power reverse connection protection circuit 10 , the third end of the fourth switch tube Q4 is connected to the input voltage bus VBB, and the second end of the fourth switch tube Q4 is connected to the second ground CGND.

[0114] Specifically, when the positive electrode of the power supply is connected to the first ground SGND and the negative electrode of the power supply is connected to the input voltage bus VBB, the first voltage is input to the third terminal S3 of the power reverse connection protection circuit 10 and is also input to the gate of the fourth switch tube Q4 to drive the fourth switch tube Q4 to turn on. Then, most of the current flows to the input voltage bus VBB through the fourth switch tube Q4. In this way, the parasitic NPN transistor composed of the input voltage bus VBB, the second ground CGND and the source of the second switch tube Q2 is effectively prevented from turning on, so that the first switch tube Q1 can be turned on smoothly.

[0115] When the power supply is positively connected, the first voltage is no longer input to the first end of the fourth switch tube Q4 , and the fourth switch tube Q4 is turned off, thereby not affecting the circuit function of the high-side switch system 100 .

[0116] In one embodiment, if Fig.12 As shown, the switch circuit 40 further includes a second Zener diode DW2 , a third resistor R3 , and a fourth resistor R4 .

[0117] Among them, the anode of the second Zener diode DW2 and the first end of the third resistor R3 are both connected to the second ground CGND, the cathode of the second Zener diode DW2 is respectively connected to the second end of the third resistor R3, the first end of the fourth resistor R4 and the first end of the fourth switch tube Q4, and the second end of the fourth resistor R4 is connected to the third end S3 of the power reverse connection protection circuit 10. In addition, this embodiment takes the third end S3 of the power reverse connection protection circuit 10 connected to the first ground SGND as an example.

[0118] Specifically, when the power supply is reversed, the diode DA1 is turned on and clamps the second ground CNGD to about 0.7V (i.e., the forward conduction voltage drop of the diode DA1). At the same time, the second Zener diode DW2 clamps the voltage input from the positive electrode of the power supply through the first ground SGND and applies it to the gate of the fourth switch tube Q4. The fourth switch tube Q4 is turned on, short-circuiting the diode DA1. At this time, most of the current flows to the input voltage bus VBB through the fourth switch tube Q4. In this way, the parasitic NPN transistor composed of the input voltage bus VBB, the second ground CGND and the source of the second switch tube Q2 is effectively prevented from being turned on, so that the first switch tube Q1 can be turned on smoothly.

[0119] When the power supply is positively connected, the third resistor R3 acts as a pull-down resistor to keep the fourth switch tube Q4 turned off, thereby not affecting the circuit function of the high-side switch system 100 .

[0120] In one embodiment, if the connection method of the third terminal S3 of the power reverse connection protection circuit 10 is as follows Figure 5 As shown, Fig.13 As shown, the switch circuit 40 further includes a fifth switch tube Q5, a sixth switch tube Q6, a third Zener diode DW3, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7. The fourth resistor R4 is connected to the third terminal S3 of the power reverse connection protection circuit 10 through the seventh resistor R7.

[0121] Among them, the third end of the fifth switch tube Q5 is connected to the first end of the fourth resistor R4 and the first end of the fourth switch tube Q4 respectively, the second end of the fifth switch tube Q5, the first end of the fifth resistor R5 and the anode of the third Zener diode DW3 are all connected to the second ground CGND, the cathode of the third Zener diode DW3 is connected to the second end of the fifth resistor R5, the second end of the sixth switch tube Q6 and the first end of the fifth switch tube Q5 respectively, the first end of the sixth switch tube Q6 is connected to the second end of the fourth resistor R4 and the second end of the seventh resistor R7 respectively, the third end of the sixth switch tube Q6 is connected to the second end of the sixth resistor R6, the first end of the seventh resistor R7 is connected to the third end S3 of the power reverse connection protection circuit 10, and the first end of the sixth resistor R6 is connected to the input voltage bus VBB.

[0122] Specifically, when the power supply is reversed, the diode DA1 is turned on and clamps the second ground CNGD to about 0.7V. The voltage of the first node CEN is the difference between the voltage of the positive electrode of the power supply and the forward conduction voltage drop of the first diode D2. The voltage of the first node CEN is applied to the gate of the fourth switch tube Q4 through the seventh resistor R7 and the fourth resistor R4, so that the fourth switch tube Q4 is turned on, thereby short-circuiting the diode DA1. At this time, most of the current flows from the second ground CGND to the input voltage bus VBB through the fourth switch tube Q4. In this way, the parasitic NPN transistor composed of the input voltage bus VBB, the second ground CGND and the source of the second switch tube Q2 is effectively prevented from being turned on, so that the first switch tube Q1 can be turned on smoothly. At the same time, the fifth switch tube Q5 and the sixth switch tube Q6 remain turned off.

[0123] When the power supply is positively connected, if the first node CEN is at a logic low level, the third resistor R3 acts as a pull-down resistor to keep the third switch tube Q3 turned off, so that the switch circuit 40 does not affect the circuit function of the high-side switch system 100. If the first node CEN is at a logic high level, the sixth switch tube Q6 is turned on, and at the same time, the voltage of the input voltage bus VBB is transmitted to the cathode of the third Zener diode DW3 through the sixth switch tube Q6 and is clamped by the third Zener diode DW3. The fifth switch tube Q5 is turned on to pull down the gate voltage of the fourth switch tube Q4. Among them, the current formed by the first node CEN at a logic high level through the seventh resistor R7 and the fourth resistor R4 to pull up the gate of the fourth switch tube Q4 is much smaller than the current that pulls down the gate of the fourth switch tube Q4 when the fifth switch tube Q5 is turned on, so the fourth switch tube Q4 can be turned off, so that the switch circuit 40 does not affect the circuit function of the high-side switch system 100.

[0124] It should be noted that Fig.13 The switch circuit 40 shown can also be applied when the connection mode of the third terminal S3 of the power reverse connection protection circuit 30 is as follows: Figure 2-Figure 4 The application scenario shown, and the working principle is also the same Fig.13 Similar, no further description is given here.

[0125] In one embodiment, if Fig.14 As shown, the high-side switch system 100 further includes a ground network 50 , a first end of the ground network 50 is connected to the first ground SGND, and a second end of the ground network 50 is connected to the second ground CGND.

[0126] The grounding network 50 includes a fourth diode D4 and an eighth resistor R8, the cathode of the fourth diode D4 and the first end of the eighth resistor R8 are both connected to the first end of the grounding network 50, and the anode of the fourth diode D4 and the second end of the eighth resistor R8 are both connected to the second end of the grounding network 50.

[0127] Specifically, when the power supply is reversely connected, the fourth diode D4 blocks the reverse current from flowing from the first ground SGND to the input voltage bus VBB. At the same time, the eighth resistor R8 effectively limits the reverse current flowing from the first SGND to the input voltage bus VBB, thereby protecting the chip (i.e., the chip where the first switch tube Q1 and the power reverse connection protection circuit 10 are located).

[0128] It can be understood that this embodiment is based on Fig.13 The circuit structure shown in the figure is added with a grounding network 50 as an example, and other embodiments, such as Figure 8-Figure 12 The circuit structure shown can also be added with a grounding network 50, and the working principle remains unchanged.

[0129] Please refer to Fig.15 , Fig.15 A flow chart of a control method for a high-side switch system provided for an embodiment of the application. The high-side switch system includes a first switch tube connected between an input voltage bus and a voltage output terminal of the high-side switch system, a load connected between the voltage output terminal of the high-side switch system and a first ground, and a power reverse connection protection circuit, wherein a first terminal of the power reverse connection protection circuit is connected to a first terminal of the first switch tube, and a second terminal of the power reverse connection protection circuit is connected to the input voltage bus. In some embodiments, the high-side switch system here can be connected as follows Figure 1-Figure 14 The structure shown in the figure is implemented, and the specific implementation process has been described in detail in the above embodiment, which will not be repeated here. Fig.15 As shown, the control method of the high-side switch system includes the following method steps:

[0130] Step 1501: When the positive pole of the power supply is connected to the first ground and the negative pole of the power supply is connected to the input voltage bus, the third terminal of the power supply reverse connection protection circuit is configured to input a first voltage to conduct a current path for current to flow from the third terminal of the power supply reverse connection protection circuit to the first terminal of the power supply reverse connection protection circuit, wherein the current path provides current to the first terminal of the first switch tube to drive the first switch tube to turn on.

[0131] Step 1502: When the positive electrode of the power source is connected to the input voltage bus and the negative electrode of the power source is connected to the first ground, disconnect the current path.

[0132] In one embodiment, the third terminal of the power reverse connection protection circuit is connected to the first ground.

[0133] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the voltage of the power supply.

[0134] In some embodiments, the high-side switch system also includes an external circuit, wherein a first end of the external circuit is connected to a third end of the power reverse protection circuit, a second end of the external circuit is connected to a first ground, and the external circuit includes a first diode, wherein an anode of the first diode is connected to the first ground, and a cathode of the first diode is connected to the first end of the external circuit.

[0135] When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the difference between the voltage of the power supply and the conduction voltage drop of the first diode.

[0136] In some embodiments, the first switch and the power reverse connection protection circuit are integrated into the same chip, the substrate of the chip is the second ground, the high-side switch system also includes a grounding network and a switch circuit, the grounding network is connected between the first ground and the second ground, and the switch circuit is connected between the input voltage bus and the second ground, wherein the grounding network includes a fourth diode and a second resistor, the cathode of the fourth diode and the first end of the second resistor are both connected to the first ground, and the anode of the fourth diode and the second end of the second resistor are both connected to the second ground. Then the control method of the high-side switch system also includes the following method steps: when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the switch circuit is turned on to short-circuit the input voltage bus and the second ground; when the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground, the switch circuit is turned off.

[0137] It should be understood that the specific control of the high-side switch system in the method embodiment and the beneficial effects produced can refer to the corresponding description in the above-mentioned embodiment of the high-side switch system, and for the sake of brevity, it will not be repeated here.

[0138] The embodiment of the present application further provides a chip, which includes the first switch tube Q1 and the power reverse connection protection circuit 10 in the high side switch system 100 in any embodiment of the present application.

[0139] An embodiment of the present application also provides an electronic device, which includes the chip in any embodiment of the present application.

[0140] The above descriptions are merely embodiments of the present application and are not intended to limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

[0141] The above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them. Under the idea of ​​the present application, the technical features in the above embodiments or different embodiments can also be combined, and the steps can be implemented in any order. It should be understood by ordinary technicians in this field that they can still modify the technical solutions recorded in the above embodiments, or replace some of the technical features by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A high side switch system, characterized in that: include: The first switch tube, the load, the power reverse connection protection circuit and the input voltage bus; The first end of the first switch tube is connected to the first end of the power reverse connection protection circuit, the second end of the first switch tube and the first end of the load are connected to the voltage output end of the high-side switch system, the third end of the first switch tube and the second end of the power reverse connection protection circuit are both connected to the input voltage bus, and the second end of the load is connected to the first ground; The power reverse connection protection circuit is configured such that when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, a first voltage is input to the third terminal of the power reverse connection protection circuit, and in response to the first voltage, a current path flowing from the third terminal of the power reverse connection protection circuit to the first terminal of the power reverse connection protection circuit is turned on, and then a current is provided to the first terminal of the first switch tube through the current path to drive the first switch tube to turn on; The power reverse connection protection circuit is further configured to disconnect the current path when the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground.

2. The high side switch system according to claim 1, characterized in that: The third terminal of the power reverse connection protection circuit is connected to the first ground, wherein when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the voltage of the power supply.

3. The high side switch system according to claim 1, characterized in that: The high-side switch system further comprises an external circuit, a first end of the external circuit is connected to a third end of the power reverse connection protection circuit, and a second end of the external circuit is connected to the first ground; The external circuit is configured to output the first voltage to the third terminal of the power reverse connection protection circuit based on the voltage of the power supply when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus.

4. The high side switch system according to claim 3, characterized in that: The external circuit includes a first diode, an anode of the first diode is connected to the first ground, and a cathode of the first diode is connected to a first end of the external circuit; When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the difference between the voltage of the power supply and the conduction voltage drop of the first diode.

5. The high side switch system according to any one of claims 1 to 4, characterized in that: The power reverse connection protection circuit comprises a second switch tube, a first Zener diode, a second diode and a first resistor; The first resistor is connected between the anode of the second diode and the first ground, the cathode of the second diode is respectively connected to the cathode of the first Zener diode and the second end of the second switch tube, the first end of the second switch tube and the anode of the first Zener diode are both connected to the input voltage bus, and the third end of the second switch tube is connected to the first end of the power reverse protection circuit.

6. The high side switch system according to claim 5, characterized in that: The power reverse connection protection circuit further includes a third switch tube and a third diode provided between the cathode of the first Zener diode and the second end of the second switch tube, wherein the second diode is a body diode of the third switch tube; The first end of the third switch tube is connected to the input voltage bus, the second end of the third switch tube is connected to the cathode of the first Zener diode and the anode of the third diode, the third end of the third switch tube is connected to the first resistor, and the cathode of the third diode is connected to the second end of the second switch tube.

7. The high side switch system according to any one of claims 1 to 6, characterized in that: The first switch tube and the power reverse connection protection circuit are integrated into the same chip, and the substrate of the chip is the second ground.

8. The high side switch system according to claim 7, characterized in that: The high-side switch system further includes a first Schottky diode; An anode of the first Schottky diode is connected to a voltage output terminal of the high-side switch system, and a cathode of the first Schottky diode is connected to the input voltage bus.

9. The high side switch system according to claim 7, characterized in that: The high-side switch system further includes a second Schottky diode; An anode of the second Schottky diode is connected to the second ground, and a cathode of the second Schottky diode is connected to the input voltage bus.

10. The high side switch system according to claim 7, characterized in that: The high-side switch system further comprises a switch circuit, wherein the switch circuit is connected between the input voltage bus and the second ground; The switch circuit is configured to be turned on when the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, so as to short-circuit the input voltage bus and the second ground; The switch circuit is further configured to be disconnected when the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground, so as to stop short-circuiting the input voltage bus and the second ground.

11. The high side switch system according to claim 10, characterized in that: The switch circuit includes a fourth switch tube; The first end of the fourth switch tube is connected to the third end of the power reverse connection protection circuit, the third end of the fourth switch tube is connected to the input voltage bus, and the second end of the fourth switch tube is connected to the second ground.

12. The high side switch system according to claim 11, characterized in that: The switch circuit also includes a second Zener diode, a third resistor and a fourth resistor; The anode of the second Zener diode and the first end of the third resistor are both connected to the second ground, the cathode of the second Zener diode is respectively connected to the second end of the third resistor, the first end of the fourth resistor and the first end of the fourth switch tube, and the second end of the fourth resistor is connected to the third end of the power reverse protection circuit.

13. The high side switch system according to claim 12, characterized in that: The switch circuit further includes a fifth switch tube, a sixth switch tube, a third Zener diode, a fifth resistor, a sixth resistor and a seventh resistor; The third end of the fifth switch tube is connected to the first end of the fourth resistor and the first end of the fourth switch tube respectively, the second end of the fifth switch tube, the first end of the fifth resistor and the anode of the third Zener diode are all connected to the second ground, the cathode of the third Zener diode is connected to the second end of the fifth resistor, the second end of the sixth switch tube and the first end of the fifth switch tube respectively, the first end of the sixth switch tube is connected to the second end of the fourth resistor and the second end of the seventh resistor respectively, the third end of the sixth switch tube is connected to the second end of the sixth resistor, the first end of the seventh resistor is connected to the third end of the power reverse protection circuit, and the first end of the sixth resistor is connected to the input voltage bus.

14. The high side switch system according to claim 7, characterized in that: The high-side switch system also includes a grounding network, a first end of the grounding network is connected to the first ground, and a second end of the grounding network is connected to the second ground, wherein the grounding network includes a fourth diode and an eighth resistor, a cathode of the fourth diode and a first end of the eighth resistor are both connected to the first end of the grounding network, and an anode of the fourth diode and a second end of the eighth resistor are both connected to the second end of the grounding network.

15. A control method for a high-side switch system, characterized in that: The high-side switch system includes a first switch tube connected between an input voltage bus and a voltage output terminal of the high-side switch system, a load connected between the voltage output terminal of the high-side switch system and a first ground, and a power reverse connection protection circuit, wherein a first terminal of the power reverse connection protection circuit is connected to a first terminal of the first switch tube, and a second terminal of the power reverse connection protection circuit is connected to the input voltage bus, and the method includes: When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the third terminal of the power supply reverse connection protection circuit is configured to input a first voltage to conduct a current path for current to flow from the third terminal of the power supply reverse connection protection circuit to the first terminal of the power supply reverse connection protection circuit, wherein the current path provides current to the first terminal of the first switch tube to drive the first switch tube to conduct; When the positive electrode of the power source is connected to the input voltage bus and the negative electrode of the power source is connected to the first ground, the current path is disconnected.

16. The method according to claim 15, characterized in that The third terminal of the power reverse connection protection circuit is connected to the first ground; When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the voltage of the power supply.

17. The method according to claim 15, characterized in that The high-side switch system further comprises an external circuit, wherein a first end of the external circuit is connected to a third end of the power reverse connection protection circuit, a second end of the external circuit is connected to the first ground, and the external circuit comprises a first diode, wherein an anode of the first diode is connected to the first ground, and a cathode of the first diode is connected to the first end of the external circuit; When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, the first voltage is equal to the difference between the voltage of the power supply and the conduction voltage drop of the first diode.

18. The method according to any one of claims 15 to 17, characterized in that: The first switch and the power reverse connection protection circuit are integrated in the same chip, the substrate of the chip is the second ground, the high-side switch system further includes a grounding network and a switch circuit, the grounding network is connected between the first ground and the second ground, the switch circuit is connected between the input voltage bus and the second ground, wherein the grounding network includes a fourth diode and an eighth resistor, the cathode of the fourth diode and the first end of the eighth resistor are both connected to the first ground, the anode of the fourth diode and the second end of the eighth resistor are both connected to the second ground, and the method further includes: When the positive electrode of the power supply is connected to the first ground and the negative electrode of the power supply is connected to the input voltage bus, turning on the switch circuit to short-circuit the input voltage bus and the second ground; When the positive electrode of the power supply is connected to the input voltage bus and the negative electrode of the power supply is connected to the first ground, the switch circuit is disconnected.

19. A chip, characterized in that: The invention comprises a first switch tube and a power reverse connection protection circuit in the high side switch system as claimed in any one of claims 1 to 12.

20. An electronic device, characterized in that: Comprising the chip as claimed in claim 19.

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