A high-side switch driving circuit with reverse high voltage protection

Abstract

The present invention provides a high-side switch driver circuit that protects against reverse high voltage, comprising a first high-voltage switch tube and a second high-voltage switch tube connected in series, a comparator circuit, and a floating power supply module. The first high-voltage switch tube is connected to a power supply, and the second high-voltage switch tube is connected to an IO port. The first high-voltage switch tube is connected to a comparator circuit for comparing the power supply voltage with the input voltage. When reverse high voltage is present, the gate of the first high-voltage switch tube is connected to the reverse high voltage, thereby turning off the first high-voltage switch tube. The floating power supply module is connected to the source of the second high-voltage switch tube and the common ground terminal of the driver stage. When the IO is at a high voltage, the floating power supply module pulls up the common ground terminal voltage of the driver stage to protect the driver stage. The present invention can drive the IO during normal operation, and can prevent reverse current from flowing into the power supply when the IO abnormally jumps high, thereby protecting the driver stage from damage.

Description

Technical Field

[0001] The present disclosure relates to the technical field of integrated circuits, and in particular to a high-side switch driving circuit that prevents reverse high voltage. Background Art

[0002] The driver stages used to drive buses or devices are divided into high-side and low-side drivers. High-side drivers pull the output stage to the high level of the power supply, while low-side drivers pull the output stage to the low level of ground. Due to various disturbances, buses or devices may see high voltages, which requires the driver stage to be able to withstand high voltages and disconnect them from the power supply.

[0003] Conventional high-side driver structures such as Figure 1 As shown, this structure prevents reverse bias by connecting the substrate to a high voltage through a substrate selection circuit. 10 is the driver stage, connecting the signal input and the high-side PMOS power transistor 15. The driver transistor 15 is connected to the power supply VDD and the IO port, driving the IO port to the VDD side. The substrate of power transistor 15 is controlled by substrate selection circuit pMOS transistors 12 and 14. When VDD is higher than the IO voltage, pMOS transistor 12 turns on and pMOS transistor 14 turns off, connecting the substrate of power transistor 15 to VDD. When VDD is lower than the IO voltage, pMOS transistor 12 turns off and pMOS transistor 14 turns on, connecting the substrate of power transistor 15 to IO. This keeps the parasitic diodes 11 and 13 of power transistor 15 in a reverse biased state, preventing current from flowing into VDD when IO is high. This circuit only activates when IO exceeds the power supply by a threshold voltage, resulting in significant reverse overcurrent. Furthermore, it cannot protect the driver stage when IO rapidly jumps to a high voltage. Summary of the Invention

[0004] In view of this, an embodiment of the present disclosure provides a high-side switch driving circuit that is resistant to reverse high voltage. The driving stage architecture of the driving circuit can drive the IO during normal operation, and can prevent the reverse current from being injected into the power supply and protect the driving stage from damage when the IO jumps abnormally high.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A high-side switch driving circuit for preventing reverse high voltage, connected to a high-side driving stage, comprising a first high-voltage switch tube and a second high-voltage switch tube connected in series, a comparator circuit and a suspended power supply module;

[0007] The drain of the first high-voltage switch tube is connected to a power supply for withstanding reverse high voltage, the drain of the second high-voltage switch tube is connected to an IO port for normally driving the IO, and the source of the first high-voltage switch tube is connected to the source of the second high-voltage switch tube;

[0008] The gate of the first high-voltage switch tube is connected to the comparator circuit, which is used to compare the power supply voltage and the input voltage. When there is a reverse high voltage, the gate of the first high-voltage switch tube is connected to the reverse high voltage, so that the first high-voltage switch tube is turned off and the reverse high voltage is blocked;

[0009] The floating power supply module is connected to the source of the second high-voltage switch tube and the common ground terminal of the driver stage, and is used to drive the second high-voltage switch tube. When IO is high voltage, the floating power supply module pulls up the common ground terminal voltage of the driver stage to protect the driver stage.

[0010] Furthermore, the floating power supply module includes a voltage stabilizing loop, to which a reference voltage of the input voltage and a common ground voltage are connected, so as to change the common ground voltage in response to changes in the reference voltage.

[0011] Furthermore, the suspension power supply module also includes a first current source, a first resistor and a first capacitor, one end of the first resistor and the first capacitor is connected to the input voltage, and the other end of the first resistor and the first capacitor is connected to the first current source, for forming the reference voltage.

[0012] Furthermore, the voltage stabilization loop includes an operational amplifier, a second current source and a first NMOS transistor, one input terminal of the operational amplifier is connected to the reference voltage, and the other input terminal is connected to the common ground terminal, one terminal of the second current source is connected to the input voltage, and the other terminal is connected to the common ground terminal and the drain of the first NMOS transistor, and the output terminal of the operational amplifier is connected to the gate of the first NMOS transistor.

[0013] Furthermore, the floating power supply module further includes a second NMOS transistor, the drain of the second NMOS transistor is connected to the input voltage, the source is connected to the common ground, and the gate is connected to the input terminal of the operational amplifier.

[0014] Furthermore, the comparator circuit includes a comparator, and the input end of the comparator includes a second resistor, a first PMOS transistor, a third resistor, a second PMOS transistor, a third current source and a fourth current source, the first end of the second resistor is connected to the power supply, and the second end is connected to the source of the first PMOS transistor, the first end of the third resistor is connected to the input voltage, and the second end is connected to the source of the second PMOS transistor, the third current source and the fourth current source are respectively connected to the drains of the first PMOS transistor and the second PMOS transistor to provide bias current; the gate of the second PMOS transistor is connected to the gate and drain of the first PMOS transistor.

[0015] Furthermore, the input end of the comparator also includes a third PMOS tube, the gate of the third PMOS tube is connected to the second end of the second resistor, and the source is connected to the second end of the third resistor, for clamping the source voltage of the second PMOS tube.

[0016] Furthermore, the output end of the comparator includes a fourth resistor, a fifth resistor, a fourth PMOS transistor, a fifth current source, a sixth current source, a first switch and a second switch, the first end of the fourth resistor is connected to the source of the first high-voltage switching transistor, the second end is connected to the gate of the first high-voltage switching transistor, the source of the fourth PMOS transistor is connected to the source of the first high-voltage switching transistor, the drain of the fourth PMOS transistor is connected to the gate of the first high-voltage switching transistor, the first end of the fifth resistor is connected to the source of the fourth PMOS transistor, and the second end is connected to the gate of the fourth PMOS transistor; the second end of the fifth resistor is connected to the fifth current source through the first switch, and the second end of the fourth resistor is connected to the sixth current source through the second switch.

[0017] Furthermore, a common terminal of the third current source, the fourth current source, the fifth current source and the sixth current source is grounded.

[0018] Furthermore, the first high-voltage switch tube and the second high-voltage switch tube are both PMOS transistors.

[0019] The present invention discloses a high-side switch driver circuit that is resistant to reverse high voltage. The driver stage architecture of the driver circuit can withstand high voltage, protect the driver stage from damage when the IO is high voltage, and prevent the high voltage from being reversely injected into the low-voltage power supply terminal. The driver circuit can be used to drive buses and various power devices. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present disclosure. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0021] Figure 1 This is a schematic diagram of the traditional high-side driver structure;

[0022] Figure 2 The high-side switch driver architecture proposed in the present invention;

[0023] Figure 3 This is a structural diagram of the suspended power supply module in the present invention;

[0024] Figure 4 Schematic diagram of the comparator circuit structure in the present invention. DETAILED DESCRIPTION

[0025] The embodiments of the present disclosure are described in detail below with reference to the accompanying drawings.

[0026] The following describes the embodiments of the present disclosure through specific examples, and those skilled in the art can easily understand other advantages and effects of the present disclosure from the contents disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all of the embodiments. The present disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0027] It should be noted that various aspects of the embodiments within the scope of the appended claims are described below. It should be apparent that the aspects described herein can be embodied in a wide variety of forms, and any specific structure and / or function described herein is merely illustrative. Based on this disclosure, it should be understood by those skilled in the art that an aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects described herein can be used to implement an apparatus and / or practice a method. In addition, other structures and / or functionalities other than one or more of the aspects described herein can be used to implement this apparatus and / or practice this method.

[0028] It should also be noted that the illustrations provided in the following embodiments are only schematic illustrations of the basic concept of the present disclosure. The illustrations only show components related to the present disclosure and are not drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component can be changed at will, and the component layout type may also be more complicated.

[0029] Additionally, in the following description, specific details are provided to provide a thorough understanding of the examples. However, one skilled in the art will appreciate that the aspects described can be practiced without these specific details.

[0030] The embodiment of the present disclosure provides a high-side switch driving circuit for preventing reverse high voltage, connected to a high-side driving stage, comprising a first high-voltage switch tube and a second high-voltage switch tube connected in series, a comparator circuit and a suspended power supply module;

[0031] The drain of the first high-voltage switch tube is connected to a power supply for withstanding reverse high voltage, the drain of the second high-voltage switch tube is connected to an IO port for normally driving the IO, and the source of the first high-voltage switch tube is connected to the source of the second high-voltage switch tube;

[0032] The gate of the first high-voltage switch tube is connected to the comparator circuit, which is used to compare the power supply voltage and the input voltage. When there is a reverse high voltage, the gate of the first high-voltage switch tube is connected to the reverse high voltage, so that the first high-voltage switch tube is turned off and the reverse high voltage is blocked;

[0033] The floating power supply module is connected to the source of the second high-voltage switch tube and the common ground terminal of the driver stage, and is used to drive the second high-voltage switch tube. When IO is high voltage, the floating power supply module pulls up the common ground terminal voltage of the driver stage to protect the driver stage.

[0034] like Figure 2 The figure shows the high-side driver stage architecture proposed in the present invention. The high-side driver stage consists of a first high-voltage switch 26 and a second high-voltage switch 24 connected in series. The first high-voltage switch 26 connects to the power supply side and the source of the second high-voltage switch 24, while the second high-voltage switch 24 connects the source of the first high-voltage switch 26 to the IO port. A comparator circuit 25 compares the Vdd voltage with the Vdd_int voltage. When Vdd is higher than Vdd_int, the comparator circuit 25 outputs a low signal, turning on the first high-voltage switch 26 and enabling the circuit to properly drive the IO port. When Vdd is lower than Vdd_int, the comparator circuit 25 outputs a high signal, turning off the first high-voltage switch 26. Simultaneously, the first parasitic diode 27 is reversely blocked, preventing the high voltage of Vdd_int from flowing back into the Vdd power supply. A floating power supply module 20 connects the source of the second high-voltage switch 24, Vdd_int, to the driver stage ground, Vss_int, to drive the second high-voltage switch 24. When IO jumps high, the second parasitic diode 28 of the second high-voltage switch 24 conducts, causing vdd_int to jump high along with IO. The floating power supply module 20 ensures that the driver-stage ground, vss_int, also jumps high. This ensures that the driver-stage level shifter 22, high-side driver 23, and the gate-source of the second high-voltage switch 24 remain at a low voltage, preventing damage when IO goes high. 21 is the low-voltage-side driver, 22 is the level shifter, and 23 is the high-side driver. The input signal Din is transmitted through the module's low-voltage-side driver 21, level shifter 22, and high-side driver 23 to the second high-voltage switch 24, controlling its normal conduction or cutoff.

[0035] like Figure 3 As shown, Figure 3The structure of the floating power supply module proposed in the present invention is shown in FIG. A first current source 32 is connected to a first resistor 31 and a first capacitor 30, forming a reference voltage vref relative to vdd_int. An operational amplifier 33 has one input terminal connected to the reference voltage vref and another input terminal connected to a common ground terminal. A second current source 36 is connected to the input voltage at one terminal and to the common ground and the drain of a first NMOS transistor 34 at the other terminal. The output terminal of the operational amplifier 33 is connected to the gate of the first NMOS transistor 34. The operational amplifier 33, the second current source 36, and the high-voltage first NMOS transistor 34 form a voltage stabilization loop, ensuring that the floating ground vss_int follows changes in the reference voltage vref. When vdd_int jumps high, the first resistor 31 and the first capacitor 30 ensure that vref follows the jump in vdd_int. The voltage stabilization loop ensures that vss_int follows the jump in vref, and thus vss_int also follows the jump in vdd_int. The second current source 36 and the first NMOS transistor 34 can provide a certain input and output current capability for vss_int. The drain of the second NMOS transistor 35 is connected to vdd_int, the source is connected to vss_int, and the gate is connected to the input of the operational amplifier 33. When vdd_int jumps high quickly, vss_int can also be quickly pulled high, providing a fast response path. At the same time, when the system vdd has no power and the first current source 32 and the second current source 36 do not provide current, vss_int will also follow vdd_int.

[0036] like Figure 4 As shown, attached Figure 4 The figure shows the anti-reverse comparator circuit structure proposed in the present invention. On the input side of comparator 47, a second resistor 40 connects vdd and a first PMOS transistor 43; a third resistor 41 connects vdd_int and a second PMOS transistor 44; a third current source 45 and a fourth current source 46 are connected to the first PMOS transistor 43 and the second PMOS transistor 44, respectively, to provide bias current. When vdd is higher than vdd_int, the drain output of the second PMOS transistor 44 is low; when vdd is lower than vdd_int, the output of the second PMOS transistor 44 is high. The gate of the third PMOS transistor 42 is connected to the lower end of the second resistor 40, and the source is connected to the lower end of the third resistor 41. This clamps the source voltage of the second PMOS transistor 44 so that it does not exceed vdd plus a threshold voltage when vdd_int is high, protecting low-voltage devices.

[0037] Comparator 47 output side: the fourth resistor 49 is connected to Figure 2 The gate Vgate and source vdd_int of the first high-voltage switch tube 26 are connected to the fourth PMOS tube 50. Figure 2The gate Vgate and source vdd_int of the first high-voltage switch transistor 26 are connected to each other, and the fifth resistor 48 is connected to the gate and source of the fourth PMOS transistor 50. When the vdd voltage is higher than vdd_int, the first switch 52 is opened, the fifth resistor 48 short-circuits the gate and source of the fourth PMOS transistor 50, and the fourth PMOS transistor 50 is turned off. The second switch 53 is closed, and the sixth current source 55 pulls down the Vgate potential through the fourth resistor 49. In this way, Figure 2 The first high-voltage switch 26 is turned on and works normally. When the vdd voltage is lower than vdd_int, the first switch 52 is closed, and the fifth current source 54 biases the gate-source of the fourth PMOS transistor 50 through the fifth resistor 48. The fourth PMOS transistor 50 is turned on, short-circuiting Vgate and Vdd_int. In this way, Figure 2 The first high-voltage switch 26 is turned off to prevent the reverse current from flowing to vdd when vdd_int is high. When the system vdd is out of power and the fifth current source 54 and the sixth current source 55 do not provide current, the fourth resistor 49 will also short-circuit the Vgate voltage to vdd_int. Figure 2 The first high-voltage switch tube 26 is in a cut-off state to prevent reverse bias.

[0038] The driver stage architecture of the present invention can drive the IO in normal operation, and can prevent the IO from reversely injecting current into the power supply and protect the driver stage from damage when the IO jumps abnormally high.

[0039] The above description is merely a specific embodiment of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims.

Claims

1. A high-side switch driving circuit for preventing reverse high voltage, connected to a high-side driving stage, characterized in that: It includes a first high-voltage switch tube and a second high-voltage switch tube connected in series, a comparator circuit and a suspension power supply module; The drain of the first high-voltage switch tube is connected to a power supply for withstanding reverse high voltage, the drain of the second high-voltage switch tube is connected to an IO port for normally driving the IO, and the source of the first high-voltage switch tube is connected to the source of the second high-voltage switch tube; The gate of the first high-voltage switch tube is connected to the comparator circuit, which is used to compare the power supply voltage and the input voltage. When there is a reverse high voltage, the gate of the first high-voltage switch tube is connected to the reverse high voltage, so that the first high-voltage switch tube is turned off and the reverse high voltage is blocked; The floating power supply module is connected to the source of the second high-voltage switch tube and the common ground terminal of the driver stage, and is used to drive the second high-voltage switch tube. When IO is high voltage, the floating power supply module pulls up the common ground terminal voltage of the driver stage to protect the driver stage; The floating power supply module includes a voltage stabilizing loop, a first current source, a first resistor and a first capacitor. The voltage stabilizing loop is connected to a reference voltage of the input voltage and a common ground voltage, so that the common ground voltage changes with changes in the reference voltage. One end of the first resistor and the first capacitor is connected to an input voltage, and the other end of the first resistor and the first capacitor is connected to the first current source, so as to form the reference voltage.

2. The high-side switch driving circuit for preventing reverse high voltage according to claim 1, characterized in that: The voltage stabilization loop includes an operational amplifier, a second current source and a first NMOS transistor. One input terminal of the operational amplifier is connected to the reference voltage, and the other input terminal is connected to the common ground. One terminal of the second current source is connected to the input voltage, and the other terminal is connected to the common ground and the drain of the first NMOS transistor. The output terminal of the operational amplifier is connected to the gate of the first NMOS transistor.

3. The high-side switch driving circuit for preventing reverse high voltage according to claim 2, characterized in that: The floating power supply module further includes a second NMOS transistor, wherein the drain of the second NMOS transistor is connected to the input voltage, the source is connected to the common ground terminal, and the gate is connected to the input terminal of the operational amplifier.

4. The high-side switch driving circuit for preventing reverse high voltage according to claim 3, characterized in that: The comparator circuit includes a comparator, wherein the input ends of the comparator include a second resistor, a first PMOS transistor, a third resistor, a second PMOS transistor, a third current source, and a fourth current source. The first end of the second resistor is connected to a power supply, and the second end is connected to the source of the first PMOS transistor. The first end of the third resistor is connected to an input voltage, and the second end is connected to the source of the second PMOS transistor. The third current source and the fourth current source are respectively connected to the drains of the first PMOS transistor and the second PMOS transistor to provide bias current. The gate of the second PMOS transistor is connected to the gate and drain of the first PMOS transistor.

5. The high-side switch driving circuit for preventing reverse high voltage according to claim 4, characterized in that: The input end of the comparator also includes a third PMOS tube, the gate of the third PMOS tube is connected to the second end of the second resistor, and the source is connected to the second end of the third resistor, for clamping the source voltage of the second PMOS tube.

6. The high-side switch driving circuit for preventing reverse high voltage according to claim 5, characterized in that: The output end of the comparator includes a fourth resistor, a fifth resistor, a fourth PMOS transistor, a fifth current source, a sixth current source, a first switch, and a second switch. The first end of the fourth resistor is connected to the source of the first high-voltage switching transistor, and the second end is connected to the gate of the first high-voltage switching transistor. The source of the fourth PMOS transistor is connected to the source of the first high-voltage switching transistor, and the drain of the fourth PMOS transistor is connected to the gate of the first high-voltage switching transistor. The first end of the fifth resistor is connected to the source of the fourth PMOS transistor, and the second end is connected to the gate of the fourth PMOS transistor. The second end of the fifth resistor is connected to the fifth current source through the first switch, and the second end of the fourth resistor is connected to the sixth current source through the second switch.

7. The high-side switch driving circuit for preventing reverse high voltage according to claim 6, characterized in that: A common terminal of the third current source, the fourth current source, the fifth current source and the sixth current source is grounded.

8. The high-side switch driving circuit for preventing reverse high voltage according to claim 1, characterized in that: The first high-voltage switch tube and the second high-voltage switch tube are both PMOS transistors.

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