Power supply anti-reverse connection circuit, power supply management chip and electronic equipment

Abstract

The invention provides a power supply anti-reverse connection circuit, a power supply management chip and electronic equipment. The power supply anti-reverse-connection circuit comprises an anti-reverse-connection circuit and a pull-down circuit. When the protected circuit is in power supply reverse connection, the pull-down circuit can pull down the potential of the control end of the reverse connection prevention circuit to the potential of the grounding end of the protected circuit, so that the reverse connection prevention circuit is turned off. Thus, when the anti-reverse-connection circuit is turned off, the body diode of the anti-reverse-connection circuit bears the voltage drop between the grounding end of the power supply anti-reverse-connection circuit and the grounding end of the protected circuit, so that the voltage drop between the power supply end of the protected circuit and the grounding end of the protected circuit is very small. Thus, internal circuit components of the protected circuit can be protected.

Description

Technical Field

[0001] The present application relates to the technical field of power management chips, and in particular to a power reverse connection protection circuit, a power management chip and an electronic device. Background Art

[0002] In the field of automotive electronics, the power pin VS1 of chips such as motor drive and high-side drive is electrically connected to the positive pole of the power supply, so that the voltage of the power pin VS1 is 5V to 40V. When the chip is in use, the power pin VS1 may be electrically connected to the negative pole of the power supply, that is, the power supply is reversed. In other words, when the power pin VS1 is connected to a low potential and the system ground pin SYSTEM_GND1 is connected to a high potential, a large voltage drop occurs between the power pin VS1 and the ground pin GND1 of the chip. As a result, the internal circuit components of the chip are damaged.

[0003] Therefore, designing a circuit to prevent internal circuit components of a chip from being damaged when the power supply is reversely connected so as to improve the reliability of the chip has become a technical problem that needs to be solved urgently. Summary of the invention

[0004] The present application provides a power reverse connection protection circuit, a power management chip and an electronic device, which can prevent damage to internal circuit components of the chip and improve the reliability of the chip.

[0005] In a first aspect, the present application provides a power supply reverse connection protection circuit, which includes: an anti-reverse connection circuit and a pull-down circuit.

[0006] The first end of the anti-reverse connection circuit and the first end of the pull-down circuit are both electrically connected to the ground end of the power supply anti-reverse connection circuit, the control end of the anti-reverse connection circuit is electrically connected to the second end of the pull-down circuit, and the second end of the anti-reverse connection circuit and the third end of the pull-down circuit are electrically connected to the ground end of the protected circuit.

[0007] The pull-down circuit is used to pull down the potential of the control end of the anti-reverse connection circuit to the potential of the ground end of the protected circuit when the protected circuit is in reverse power supply, so as to shut down the anti-reverse connection circuit.

[0008] The anti-reverse connection circuit is used for, when turned off, the body diode of the anti-reverse connection circuit bears the voltage drop between the ground terminal of the power anti-reverse connection circuit and the ground terminal of the protected circuit, so as to protect the internal circuit components of the protected circuit.

[0009] Through the power reverse connection protection circuit provided in the first aspect, when the protected circuit is in power reverse connection, the pull-down circuit can pull down the potential of the control end of the anti-reverse connection circuit to the potential of the ground end of the protected circuit, so that the anti-reverse connection circuit is turned off. In this way, when the anti-reverse connection circuit is turned off, the body diode of the anti-reverse connection circuit bears the voltage drop between the ground end of the power reverse connection protection circuit and the ground end of the protected circuit, so that the voltage drop between the power supply end of the protected circuit and the ground end of the protected circuit is very small. Thereby, the internal circuit components of the protected circuit can be protected.

[0010] In a possible design, the control end of the anti-reverse connection circuit is also used to access a bias voltage, and the bias voltage is used to control the on or off of the anti-reverse connection circuit.

[0011] The pull-down circuit is also used to shut down when the protected circuit is not in the state of reverse power connection.

[0012] The reverse connection protection circuit is also used to be turned on according to the bias voltage when the pull-down circuit is turned off, so that the working current of the protected circuit flows into the ground terminal of the power reverse connection protection circuit.

[0013] Based on this, when the protected circuit is not in the reverse connection of the power supply, the pull-down circuit is turned off. In this way, when the pull-down circuit is turned off, under the action of the bias voltage, the sixth transistor is turned on and is in the linear region. Furthermore, the anti-reverse connection circuit can be turned on according to the bias voltage, so that the working current of the protected circuit can flow into the ground terminal of the power reverse connection protection circuit through the turned-on anti-reverse connection circuit.

[0014] In one possible design, the pull-down circuit includes: a driving component and a first transistor.

[0015] The first end of the driving component is electrically connected to the ground terminal of the power reverse connection protection circuit, the second end of the driving component is electrically connected to the control end of the first transistor, the first end of the first transistor is electrically connected to the control end of the reverse connection protection circuit, and the second end of the first transistor and the third end of the driving component are both electrically connected to the ground terminal of the protected circuit.

[0016] The driving component is used to be turned on when the protected circuit is in reverse power supply, so as to turn on the first transistor, so that the potential of the control end of the anti-reverse connection circuit is pulled down to the potential of the ground end of the protected circuit.

[0017] Based on this, when the protected circuit is in the state of reverse power connection, the driving component is turned on, so that the first transistor is turned on, so that the potential of the control terminal of the anti-reverse connection circuit is pulled down to the potential of the ground terminal of the protected circuit. Thus, when the protected circuit is in the state of reverse power connection, the pull-down circuit can pull down the potential of the control terminal of the anti-reverse connection circuit to the potential of the ground terminal of the protected circuit.

[0018] In one possible design, the driving component includes: a first resistor, a second transistor, a third transistor, a fourth transistor, and a fifth transistor.

[0019] The first end of the first resistor is electrically connected to the ground terminal of the power supply reverse connection protection circuit, the second end of the first resistor is electrically connected to the second end of the second transistor, the control end of the second transistor and the control end of the reverse connection protection circuit, the first end of the second transistor is electrically connected to the second end of the third transistor and the control end of the third transistor, the first end of the third transistor is electrically connected to the second end of the fourth transistor and the control end of the fourth transistor, the first end of the fourth transistor is electrically connected to the second end of the fifth transistor and the control end of the fifth transistor, and the first end of the fifth transistor is electrically connected to the ground terminal of the protected circuit.

[0020] Based on this, when the protected circuit is in the reverse power state, the driving component is turned on. In this way, the potential of the second end of the first resistor is clamped at a high potential by the second transistor, the third transistor, the fourth transistor and the fifth transistor, so that the first transistor is turned on. In this way, under the action of the turned-on first transistor, the potential of the control end of the anti-reverse connection circuit is pulled down to the potential of the ground end of the protected circuit, so that the anti-reverse connection circuit is shut down. Therefore, when the protected circuit is in the reverse power state, the pull-down circuit can pull down the potential of the control end of the anti-reverse connection circuit to the potential of the ground end of the protected circuit.

[0021] In one possible design, the reverse connection protection circuit includes: a sixth transistor.

[0022] The second end of the sixth transistor is electrically connected to the ground end of the power reverse connection protection circuit, the control end of the sixth transistor is electrically connected to the second end of the pull-down circuit, and the first end of the sixth transistor is electrically connected to the ground end of the protected circuit.

[0023] In a possible design, the power supply reverse connection protection circuit further includes: a second resistor, wherein a difference between an impedance of the second resistor and an on-impedance of the reverse connection protection circuit is greater than a preset impedance.

[0024] The first end of the second resistor is electrically connected to the ground terminal of the power reverse connection protection circuit, and the second end of the second resistor is electrically connected to the ground terminal of the protected circuit.

[0025] Based on this, the difference between the impedance of the second resistor and the on-impedance of the anti-reverse connection circuit is greater than the preset impedance. Since the preset impedance is large, the on-impedance of the anti-reverse connection circuit is much smaller than the impedance of the second resistor. In this way, when the protected circuit is in the reverse connection of the power supply, the current flowing to the protected circuit is very small through the current limiting of the second resistor.

[0026] In a possible design, the power supply reverse connection protection circuit further includes: a transistor group and a third resistor.

[0027] The first end of the transistor group is electrically connected to the ground end of the power supply reverse connection protection circuit, the second end of the transistor group is electrically connected to the control end of the reverse connection protection circuit, the control end of the transistor group is electrically connected to the first end of the third resistor, and the second end of the third resistor is electrically connected to the ground end of the protected circuit.

[0028] In one possible design, the transistor group includes: a seventh transistor and an eighth transistor.

[0029] The second end of the seventh transistor is electrically connected to the ground end of the power supply reverse connection protection circuit, the first end of the seventh transistor is electrically connected to the first end of the eighth transistor, the second end of the eighth transistor is electrically connected to the control end of the reverse connection protection circuit, and the control end of the seventh transistor and the control end of the eighth transistor are both electrically connected to the first end of the third resistor.

[0030] In one possible design, the power supply reverse connection protection circuit also includes: a ninth transistor and a tenth transistor.

[0031] The control end of the ninth transistor, the first end of the ninth transistor, the control end of the tenth transistor and the first end of the tenth transistor are all electrically connected to the ground end of the protected circuit, the second end of the ninth transistor is electrically connected to the control end of the seventh transistor, and the second end of the tenth transistor is electrically connected to the second end of the eighth transistor.

[0032] Based on this, when the voltage at the ground terminal of the power reverse connection protection circuit jumps, the potential of the control terminal of the seventh transistor is kept stable through the ninth transistor, and the potential of the second terminal of the eighth transistor is kept stable through the tenth transistor.

[0033] In a second aspect, the present application provides a power management chip, comprising: a protected circuit and a power reverse connection protection circuit in the above-mentioned first aspect and any possible design of the first aspect.

[0034] The power reverse connection protection circuit is electrically connected between the ground terminal of the protected circuit and the system ground terminal of the power management chip.

[0035] The beneficial effects of the power management chip provided in the above-mentioned second aspect and each possible design of the above-mentioned second aspect can be referred to the beneficial effects brought about by the above-mentioned first aspect and each possible implementation method of the first aspect, and will not be repeated here.

[0036] In a fourth aspect, the present application provides an electronic device, comprising: the chip in the third aspect above.

[0037] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0039] Figure 1 It is a structural schematic diagram of a power supply reverse connection protection circuit in the related art;

[0040] Figure 2 A schematic diagram of the structure of a power management chip provided in one embodiment of the present application;

[0041] Figure 3 A schematic diagram of the structure of a power supply reverse connection protection circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0042] In this application, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent: A exists alone, A and B exist at the same time, and B exists alone, where A and B can be singular or plural. The character " / " generally indicates that the associated objects before and after are in an "or" relationship. "At least one of the following" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b, or c alone can represent: a, b, c, a and b, a and c, or a, b, and c, where a, b, and c can be single or multiple. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0043] The directions or positional relationships indicated by terms such as "center", "longitudinal", "lateral", "up", "down", "left", "right", "front", and "back" are based on the directions or positional relationships shown in the accompanying drawings and are only for the convenience of describing the present application and simplifying the description. They do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore should not be understood as a limitation on the present application.

[0044] The terms "connected" and "connected" should be understood in a broad sense. For example, the "connected" or "connected" of a circuit structure can refer to not only physical connection, but also electrical connection or signal connection. For example, it can be directly connected, that is, physically connected, or indirectly connected through at least one intermediate element, as long as the circuit is connected, or it can be the internal connection of two elements; signal connection can refer to signal connection through a circuit or through a media medium, such as radio waves. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0045] In the field of automotive electronics, the power pin VS1 of chips such as motor drive and high-side drive is electrically connected to the positive pole of the power supply, so that the voltage of the power pin VS1 is 5V to 40V. When the chip is in use, the power pin VS1 may be electrically connected to the negative pole of the power supply, that is, the power supply is reversed. In other words, when the power pin VS1 is connected to a low potential and the system ground pin SYSTEM_GND1 is connected to a high potential, a large voltage drop occurs between the power pin VS1 and the ground pin GND1 of the chip. As a result, the internal circuit components of the chip are damaged.

[0046] Reference Figure 1 , Figure 1 FIG. 1 is a schematic diagram of a power supply reverse connection protection circuit in the related art. Figure 1 As shown, a Schottky diode Ds and a resistor Rs are connected in series between the system ground pin SYSTEM_GND1 and the ground pin GND1 of the chip. When the power pin VS1 is connected normally, the Schottky diode Ds is forward-conducted, so that the working current of the chip flows into the system ground pin SYSTEM_GND1 through the Schottky diode Ds.

[0047] When the power pin VS1 is reversely connected, the Schottky diode Ds is reversely cut off, so that the voltage drop between the system ground pin SYSTEM_GND1 and the power pin VS1 is basically dropped on the reverse-cut-off Schottky diode Ds. Thus, it is ensured that there is no large voltage drop between the power pin VS1 of the chip and the ground pin GND1 of the chip, so as to play the role of reverse connection protection.

[0048] At the same time, when the power pin VS1 is reversely connected, the current flowing into the chip can be very small through the current limiting of the resistor Rs.

[0049] However, since the related art requires discrete components of Schottky diode Ds and resistor Rs, the power reverse connection protection circuit in the related art has the problem of high cost. At the same time, when the chip power pin VS1 is normally connected, the voltage of the chip ground pin GND1 is higher than the system ground pin SYSTEM_GND1 by the forward conduction voltage drop of a Schottky diode Ds, and the conduction voltage drop of the Schottky diode Ds is relatively high.

[0050] The present application provides a power reverse connection protection circuit, a power management chip and an electronic device.

[0051] The power reverse connection protection circuit may be a chip or a circuit module.

[0052] Reference Figure 2 , Figure 2 This is a schematic diagram of the structure of a power management chip provided in one embodiment of the present application. Figure 2 As shown, the power management chip 1000 may include: a protected circuit 200 and a power reverse connection protection circuit 100 .

[0053] The power reverse connection protection circuit 100 is electrically connected between the ground terminal GND2 of the protected circuit 200 and the system ground terminal of the power management chip 1000 .

[0054] Among them, the power supply terminal VS2 of the protected circuit 200 is electrically connected to the positive pole of the power supply, the ground terminal GND2 of the protected circuit 200 is electrically connected to the power supply terminal of the power reverse connection protection circuit 100, and the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 is electrically connected to the negative pole of the power supply.

[0055] Since all circuits integrated in the power management chip 1000 have corresponding ground terminals, the power management chip 1000 may have multiple ground terminals, while the power management chip 1000 has only one system ground terminal.

[0056] When the power management chip 1000 is a chip, by integrating the power reverse connection protection circuit 100 into the power management chip 1000, it is possible to avoid using discrete devices to perform power reverse connection protection on the protected circuit 200, thereby reducing costs.

[0057] The protected circuit 200 may be, for example, a motor drive circuit and a high-side drive circuit, or other circuits that require power reverse connection protection. For ease of description, the embodiments of the present application are described using a drive circuit as an example.

[0058] In this application, electronic devices may include, but are not limited to: household appliances, automotive electronics, industrial automation, and smart homes.

[0059] When the protected circuit 200 is in the power reverse connection state, the voltage drop between the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 and the ground terminal GND2 of the protected circuit 200, that is, the reverse connection voltage is very large. At this time, the reverse connection voltage is basically dropped on the power reverse connection protection circuit 100. Therefore, it is possible to avoid a large voltage drop between the power terminal VS2 of the protected circuit 200 and the ground terminal GND2 of the protected circuit 200, so as to protect the internal circuit components of the protected circuit 200.

[0060] When the protected circuit 200 is not in reverse power state, the power reverse connection protection circuit 100 generates a current path from the ground terminal GND2 of the protected circuit 200 to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100, so that the protected circuit 200 can work normally.

[0061] Reference Figure 3 , Figure 3 Shows Figure 2 A schematic diagram of a power supply reverse connection protection circuit. Figure 3 As shown, the power reverse connection protection circuit 100 may include: a reverse connection protection circuit 110 and a pull-down circuit 120 .

[0062] The first end of the anti-reverse connection circuit 110 and the first end of the pull-down circuit 120 are both electrically connected to the ground terminal SYSTEM_GND2 of the power supply anti-reverse connection circuit 100, the control end of the anti-reverse connection circuit 110 is electrically connected to the second end of the pull-down circuit 120, and the second end of the anti-reverse connection circuit 110 and the third end of the pull-down circuit 120 are electrically connected to the ground terminal GND2 of the protected circuit 200.

[0063] The anti-reverse connection circuit 110 and the pull-down circuit 120 may be provided separately or integratedly.

[0064] Figure 3 In the figure, the first end of the anti-reverse connection circuit 110 is recorded as 1, the control end of the anti-reverse connection circuit 110 is recorded as 2, the second end of the anti-reverse connection circuit 110 is recorded as 3, the first end of the pull-down circuit 120 is recorded as 1, the second end of the pull-down circuit 120 is recorded as 2, and the third end of the pull-down circuit 120 is recorded as 3.

[0065] In some examples, the reverse connection prevention circuit 110 may include: a sixth transistor M6 .

[0066] The second end of the sixth transistor M6 is electrically connected to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 , the control end of the sixth transistor M6 is electrically connected to the second end of the pull-down circuit 120 , and the first end of the sixth transistor M6 is electrically connected to the ground terminal GND2 of the protected circuit 200 .

[0067] The second end of the sixth transistor M6 is the first end of the anti-reverse connection circuit 110 , the control end of the sixth transistor M6 is the control end of the anti-reverse connection circuit 110 , and the first end of the sixth transistor M6 is the second end of the anti-reverse connection circuit 110 .

[0068] When the protected circuit 200 is in the reverse power state, the pull-down circuit 120 can pull down the potential of the control terminal of the anti-reverse connection circuit 110 to the potential of the ground terminal GND2 of the protected circuit 200, so that the anti-reverse connection circuit 110 is turned off. In this way, when the anti-reverse connection circuit 110 is turned off, the body diode D1 of the anti-reverse connection circuit 110, that is, the body diode D1 of the sixth transistor M6 can withstand the voltage drop between the ground terminal SYSTEM_GND2 of the power anti-reverse connection circuit 100 and the ground terminal GND2 of the protected circuit 200, that is, the reverse voltage is basically dropped on the body diode D1 of the anti-reverse connection circuit 110, so that the voltage drop between the power terminal VS2 of the protected circuit 200 and the ground terminal GND2 of the protected circuit 200 is very small. Thereby, the internal circuit components of the protected circuit 200 can be protected.

[0069] In some examples, the control terminal of the anti-reverse connection circuit 110 is also used to access a bias voltage VBIAS, and the bias voltage VBIAS is used to control the on or off of the anti-reverse connection circuit 110 .

[0070] When the protected circuit 200 is not in the state of reverse power connection, the level of the bias voltage VBIAS is high.

[0071] When the protected circuit 200 is not in the power reverse connection state, the pull-down circuit 120 is turned off. Thus, when the pull-down circuit 120 is turned off, under the action of the bias voltage VBIAS, the sixth transistor M6 is turned on and is in the linear region. Furthermore, the anti-reverse connection circuit 110 can be turned on according to the bias voltage VBIAS, so that the working current of the protected circuit 200 can flow into the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 through the turned-on anti-reverse connection circuit 110.

[0072] The power reverse connection protection circuit, system, chip and electronic device provided by the present application can, when the protected circuit is in reverse connection, pull down the potential of the control end of the anti-reverse connection circuit to the potential of the ground end of the protected circuit, so that the anti-reverse connection circuit is turned off. In this way, when the anti-reverse connection circuit is turned off, the body diode of the anti-reverse connection circuit bears the voltage drop between the ground end of the power reverse connection protection circuit and the ground end of the protected circuit, so that the voltage drop between the power supply end of the protected circuit and the ground end of the protected circuit is very small. Thus, the internal circuit components of the protected circuit can be protected.

[0073] Based on the description of the above embodiment, a possible implementation of the pull-down circuit 120 is exemplified. Figure 3As shown, the pull-down circuit 120 may include: a driving component 121 and a first transistor M1.

[0074] The first end of the driving component 121 is electrically connected to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100, the second end of the driving component 121 is electrically connected to the control end of the first transistor M1, the first end of the first transistor M1 is electrically connected to the control end of the reverse connection protection circuit 110, and the second end of the first transistor M1 and the third end of the driving component 121 are both electrically connected to the ground terminal GND2 of the protected circuit 200.

[0075] The first end of the driving component 121 is the first end of the pull-down circuit 120 , the first end of the first transistor M1 is the second end of the pull-down circuit 120 , and the second end of the first transistor M1 and the third end of the driving component 121 are both the third ends of the pull-down circuit 120 .

[0076] In some examples, the driving component 121 may include: a first resistor R1 , a second transistor M2 , a third transistor M3 , a fourth transistor M4 , and a fifth transistor M5 .

[0077] The first end of the first resistor R1 is electrically connected to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100, the second end C of the first resistor R1 is electrically connected to the second end of the second transistor M2, the control end of the second transistor M2 and the control end of the reverse connection protection circuit 110, the first end of the second transistor M2 is electrically connected to the second end of the third transistor M3 and the control end of the third transistor M3, the first end of the third transistor M3 is electrically connected to the second end of the fourth transistor M4 and the control end of the fourth transistor M4, the first end of the fourth transistor M4 is electrically connected to the second end of the fifth transistor M5 and the control end of the fifth transistor M5, and the first end of the fifth transistor M5 is electrically connected to the ground terminal GND2 of the protected circuit 200.

[0078] The first end of the first resistor R1 is the first end of the driving component 121 , the second end C of the first resistor R1 is the second end of the driving component 121 , and the first end of the fifth transistor M5 is the third end of the driving component 121 .

[0079] When the protected circuit 200 is in the state of reverse power connection, the voltage drop between the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 and the ground terminal GND2 of the protected circuit 200 is very large, so that the driving component 121 is turned on. In this way, the potential of the second end C of the first resistor R1 is clamped at a high potential by the second transistor M2, the third transistor M3, the fourth transistor M4 and the fifth transistor M5, so that the first transistor M1 is turned on. In this way, under the action of the turned-on first transistor M1, the potential of the control end of the anti-reverse connection circuit 110 is pulled down to the potential of the ground terminal GND2 of the protected circuit 200, so that the anti-reverse connection circuit 110 is shut down. Therefore, when the protected circuit 200 is in the state of reverse power connection, the pull-down circuit 120 can pull down the potential of the control end of the anti-reverse connection circuit 110 to the potential of the ground terminal GND2 of the protected circuit 200.

[0080] When the first transistor M1 is turned on, the first transistor M1 still operates in the linear region.

[0081] When the protected circuit 200 is not in the state of reverse power connection, the voltage drop between the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 and the ground terminal GND2 of the protected circuit 200 is zero, so that the driving component 121 is turned off. In this way, the potential of the second end C of the first resistor R1 is not enough to turn on the first transistor M1, so that the first transistor M1 is turned off. Therefore, when the protected circuit 200 is not in the state of reverse power connection, the pull-down circuit 120 is turned off.

[0082] In summary, when the protected circuit is in the state of reverse power connection, the driving component is turned on, so that the first transistor is turned on, so that the potential of the control terminal of the anti-reverse connection circuit is pulled down to the potential of the ground terminal of the protected circuit. Thus, when the protected circuit is in the state of reverse power connection, the pull-down circuit can pull down the potential of the control terminal of the anti-reverse connection circuit to the potential of the ground terminal of the protected circuit.

[0083] Based on the description of the above embodiment, another possible implementation of the power reverse connection protection circuit 100 is exemplified. Figure 3 As shown, the power reverse connection protection circuit 100 may further include: a second resistor R2.

[0084] A first end of the second resistor R2 is electrically connected to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 , and a second end of the second resistor R2 is electrically connected to the ground terminal GND2 of the protected circuit 200 .

[0085] The difference between the impedance of the second resistor R2 and the on-resistance Ron of the anti-reverse connection circuit 110 is greater than the preset impedance. Since the preset impedance is large, the on-resistance Ron of the anti-reverse connection circuit 110 is much smaller than the impedance of the second resistor R2.

[0086] When the power supply of the protected circuit 200 is reversely connected, the current flowing to the protected circuit 200 is very small due to the current limiting of the second resistor R2.

[0087] When the protected circuit 200 is not in the reverse power state, the on-resistance Ron of the reverse power protection circuit 110 is very small, so that the voltage drop between the ground terminal SYSTEM_GND2 of the power reverse power protection circuit 100 and the ground terminal GND2 of the protected circuit 200 is very small, almost zero. Therefore, it is possible to prevent the ground terminal GND2 of the protected circuit 200 from being raised to the forward conduction voltage drop of a Schottky diode Ds. At the same time, since the impedance of the second resistor R2 is very large, the current on the second resistor R2 is very small.

[0088] In summary, the difference between the impedance of the second resistor and the on-impedance of the anti-reverse connection circuit is greater than the preset impedance. Since the preset impedance is large, the on-impedance of the anti-reverse connection circuit is much smaller than the impedance of the second resistor. In this way, when the protected circuit is in the reverse connection of the power supply, the current flowing to the protected circuit is very small through the current limiting of the second resistor.

[0089] Based on the description of the above embodiment, another possible implementation of the power reverse connection protection circuit 100 is exemplified. Figure 3 As shown, the power reverse connection protection circuit 100 may further include: a transistor group 130 and a third resistor R3.

[0090] The first end of the transistor group 130 is electrically connected to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100, the second end of the transistor group 130 is electrically connected to the control end of the reverse connection protection circuit 110, the control end of the transistor group 130 is electrically connected to the first end of the third resistor R3, and the second end of the third resistor R3 is electrically connected to the ground terminal GND2 of the protected circuit 200.

[0091] In some examples, transistor group 130 may include a seventh transistor M7 and an eighth transistor M8 .

[0092] The second end of the seventh transistor M7 is electrically connected to the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100, the first end of the seventh transistor M7 is electrically connected to the first end of the eighth transistor M8, the second end B of the eighth transistor M8 is electrically connected to the control end of the reverse connection protection circuit 110, and the control end A of the seventh transistor M7 and the control end of the eighth transistor M8 are both electrically connected to the first end of the third resistor R3.

[0093] The second end of the seventh transistor M7 is the first end of the transistor group 130 , the second end B of the eighth transistor M8 is the second end of the transistor group 130 , and the control end A of the seventh transistor M7 and the control end of the eighth transistor M8 are both control ends of the transistor group 130 .

[0094] When the protected circuit 200 is in reverse power supply, the third resistor R3 pulls down the potential of the control terminal A of the seventh transistor M7 to the potential of the ground terminal GND2 of the protected circuit 200, so that the seventh transistor M7 and the eighth transistor M8 are both turned off, and the transistor group 130 is turned off.

[0095] When the protected circuit 200 is in the reverse power state and the voltage of the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 changes, the potential of the second terminal B of the eighth transistor M8 will suddenly change to a high potential, so that the reverse connection protection circuit 110 is turned on. As a result, the voltage change of the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 disappears, so that the voltage of the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 tends to be stable. As a result, the transistor group 130 can turn on the reverse connection protection circuit 110, so that the voltage of the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 is stable.

[0096] When the protected circuit 200 is not in reverse power connection, the voltage drop between the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 and the ground terminal GND2 of the protected circuit 200 is zero, so that the seventh transistor M7 and the eighth transistor M8 are both turned off.

[0097] Since the body diode D2 of the seventh transistor M7 and the body diode D3 of the eighth transistor M8 form a back-to-back structure, there is no forward-conducting PN junction path between the control end of the anti-reverse connection circuit 110 and the ground end SYSTEM_GND2 of the power anti-reverse connection circuit 100, thereby preventing the bias voltage VBIAS from flowing to the ground end SYSTEM_GND2 of the power anti-reverse connection circuit 100 through the body diode D2 of the seventh transistor M7.

[0098] The sixth transistor M6 , the seventh transistor M7 and the eighth transistor M8 are all high-voltage transistors, which can withstand the voltage drop between the power terminal VS2 of the protected circuit 200 and the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 .

[0099] Based on the description of the above embodiment, another possible implementation of the power reverse connection protection circuit 100 is exemplified. Figure 3 As shown, the power reverse connection protection circuit 100 may further include: a ninth transistor M9 and a tenth transistor M10.

[0100] The control end of the ninth transistor M9, the first end of the ninth transistor M9, the control end of the tenth transistor M10 and the first end of the tenth transistor M10 are all electrically connected to the ground terminal GND2 of the protected circuit 200, the second end of the ninth transistor M9 is electrically connected to the control end of the seventh transistor M7, and the second end of the tenth transistor M10 is electrically connected to the second end of the eighth transistor M8.

[0101] When the voltage of the ground terminal SYSTEM_GND2 of the power reverse connection protection circuit 100 changes, the potential of the control terminal A of the seventh transistor M7 is kept stable through the ninth transistor M9, and the potential of the second terminal B of the eighth transistor M8 is kept stable through the tenth transistor M10.

[0102] In summary, when the voltage at the ground terminal of the power reverse connection protection circuit jumps, the potential of the control terminal of the seventh transistor is kept stable through the ninth transistor, and the potential of the second terminal of the eighth transistor is kept stable through the tenth transistor.

[0103] It should be noted that: Figure 3 The transistor in the embodiment may be a metal oxide semiconductor field effect transistor device. At the same time, the transistor may also be an insulated gate bipolar transistor device, an integrated gate rectifier thyristor device, a gate turn-off thyristor device, a silicon controlled rectifier device, a junction gate field effect transistor device, a MOS controlled thyristor device, a gallium nitride-based power device, a silicon nitride-based power device, etc. The embodiments of the present application do not specifically limit this.

[0104] Finally, it should be noted that the above embodiments are only specific implementation methods of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope disclosed in the present application should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

Claims

1. A power supply reverse connection protection circuit, It is characterized in that The power supply reverse connection protection circuit comprises: a reverse connection protection circuit and a pull-down circuit; The first end of the anti-reverse connection circuit and the first end of the pull-down circuit are both electrically connected to the ground end of the power anti-reverse connection circuit, the control end of the anti-reverse connection circuit is electrically connected to the second end of the pull-down circuit, and the second end of the anti-reverse connection circuit and the third end of the pull-down circuit are electrically connected to the ground end of the protected circuit; The pull-down circuit is used to pull down the potential of the control end of the anti-reverse connection circuit to the potential of the ground end of the protected circuit when the protected circuit is in reverse power connection, so as to turn off the anti-reverse connection circuit; The anti-reverse connection circuit is used for protecting the internal circuit components of the protected circuit by allowing the body diode of the anti-reverse connection circuit to withstand the voltage drop between the ground terminal of the power anti-reverse connection circuit and the ground terminal of the protected circuit when the anti-reverse connection circuit is turned off.

2. The circuit according to claim 1, It is characterized in that The control end of the anti-reverse connection circuit is also used to access a bias voltage, and the bias voltage is used to control the on or off of the anti-reverse connection circuit; The pull-down circuit is further used to shut down when the protected circuit is not in a state of reverse power connection; The reverse connection protection circuit is also used to be turned on according to the bias voltage when the pull-down circuit is turned off, so that the working current of the protected circuit flows into the ground terminal of the power reverse connection protection circuit.

3. The circuit according to claim 2, It is characterized in that The pull-down circuit comprises: a driving component and a first transistor; The first end of the driving component is electrically connected to the ground end of the power reverse connection protection circuit, the second end of the driving component is electrically connected to the control end of the first transistor, the first end of the first transistor is electrically connected to the control end of the reverse connection protection circuit, and the second end of the first transistor and the third end of the driving component are both electrically connected to the ground end of the protected circuit; The driving component is used to be turned on when the protected circuit is in reverse power supply, so as to turn on the first transistor, so that the potential of the control end of the anti-reverse connection circuit is pulled down to the potential of the ground end of the protected circuit.

4. The circuit according to claim 3, It is characterized in that The driving component includes: a first resistor, a second transistor, a third transistor, a fourth transistor and a fifth transistor; The first end of the first resistor is electrically connected to the ground terminal of the power supply reverse connection protection circuit, the second end of the first resistor is electrically connected to the second end of the second transistor, the control end of the second transistor and the control end of the reverse connection protection circuit, the first end of the second transistor is electrically connected to the second end of the third transistor and the control end of the third transistor, the first end of the third transistor is electrically connected to the second end of the fourth transistor and the control end of the fourth transistor, the first end of the fourth transistor is electrically connected to the second end of the fifth transistor and the control end of the fifth transistor, and the first end of the fifth transistor is electrically connected to the ground terminal of the protected circuit.

5. The circuit according to claim 1, It is characterized in that The reverse connection prevention circuit comprises: a sixth transistor; The second end of the sixth transistor is electrically connected to the ground end of the power reverse connection protection circuit, the control end of the sixth transistor is electrically connected to the second end of the pull-down circuit, and the first end of the sixth transistor is electrically connected to the ground end of the protected circuit.

6. The circuit according to any one of claims 1 to 5, It is characterized in that The power supply reverse connection protection circuit further includes: a second resistor, wherein the difference between the impedance of the second resistor and the on-impedance of the reverse connection protection circuit is greater than a preset impedance; The first end of the second resistor is electrically connected to the ground terminal of the power reverse connection protection circuit, and the second end of the second resistor is electrically connected to the ground terminal of the protected circuit.

7. The circuit according to claim 6, It is characterized in that The power supply reverse connection protection circuit further includes: a transistor group and a third resistor; The first end of the transistor group is electrically connected to the ground end of the power supply reverse connection protection circuit, the second end of the transistor group is electrically connected to the control end of the reverse connection protection circuit, the control end of the transistor group is electrically connected to the first end of the third resistor, and the second end of the third resistor is electrically connected to the ground end of the protected circuit.

8. The circuit according to claim 7, It is characterized in that The transistor group includes: a seventh transistor and an eighth transistor; The second end of the seventh transistor is electrically connected to the ground end of the power supply reverse connection protection circuit, the first end of the seventh transistor is electrically connected to the first end of the eighth transistor, the second end of the eighth transistor is electrically connected to the control end of the reverse connection protection circuit, and the control end of the seventh transistor and the control end of the eighth transistor are both electrically connected to the first end of the third resistor.

9. The circuit according to claim 8, It is characterized in that The power supply reverse connection protection circuit further includes: a ninth transistor and a tenth transistor; The control end of the ninth transistor, the first end of the ninth transistor, the control end of the tenth transistor and the first end of the tenth transistor are all electrically connected to the ground end of the protected circuit, the second end of the ninth transistor is electrically connected to the control end of the seventh transistor, and the second end of the tenth transistor is electrically connected to the second end of the eighth transistor.

10. A power management chip, It is characterized in that include: A protected circuit and a power supply reverse connection protection circuit as claimed in any one of claims 1 to 9; The power reverse connection protection circuit is electrically connected between the ground terminal of the protected circuit and the system ground terminal of the power management chip.

11. An electronic device, It is characterized in that include: The power management chip as claimed in claim 10.

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