Gate driving voltage control circuit, power supply module and vehicle

Abstract

The invention discloses a grid driving voltage control circuit, a power module and a vehicle, the circuit comprises a power supply unit, and the power supply unit comprises a power supply and an MOS tube; the control unit comprises a main driving circuit, a standby driving circuit, a comparison module, a voltage sampling circuit and a charge pump, the main driving circuit is connected with the input end of the charge pump, the output end of the charge pump is connected with the grid electrode of the MOS tube, and the signal output end of the voltage sampling circuit is connected with the input end of the comparison module. The comparison module is connected with the control end of the main drive circuit and the control end of the standby drive circuit. The output end of the standby driving circuit is connected with the input end of the charge pump, and the comparison module compares the voltage sampling value with the voltage upper limit value and the voltage lower limit value and controls the output of the main driving circuit and the standby driving circuit according to the comparison result. The device can well adapt to the low-pressure working condition and the high-pressure working condition and is high in reliability.

Description

Technical Field

[0001] This application relates to the field of MOSFET driving, and in particular to a gate drive voltage control circuit, a power supply module, and a vehicle. Background Technology

[0002] A MOSFET mainly consists of a source (S), a drain (D), and a gate (G). Its operating principle is based on the electric field effect. When a voltage higher than the gate drive voltage threshold (VGSth) is applied between the gate and source, a channel is formed below the gate for conduction. When the voltage is lower than VGSth, the conduction channel is small, and the MOSFET is turned off. In applications, to ensure the MOSFET can pass the charge pump, the gate voltage is raised to nearly twice the voltage value. However, under low-voltage conditions, even with a voltage increase to twice the value, it is still below the MOSFET's drive voltage threshold, and the MOSFET remains off, preventing it from functioning. Furthermore, under high-voltage conditions, excessively high gate voltages can damage the MOSFET.

[0003] In summary, the MOSFET control circuits in related technologies cannot adapt well to low-voltage and high-voltage operating conditions, resulting in low reliability. Summary of the Invention

[0004] This application proposes a gate drive voltage control circuit, a power supply module, and a vehicle, which can adapt well to both low-voltage and high-voltage operating conditions and has high reliability.

[0005] The gate drive voltage control circuit according to the first aspect embodiment of this application includes: A power supply unit, comprising a power supply and a MOSFET, wherein the power supply is connected to the drain of the MOSFET and the source of the MOSFET is used to connect to a peripheral load; The control unit includes a main drive circuit, a backup drive circuit, a comparison module, a voltage sampling circuit, and a charge pump. The main drive circuit provides a drive enable voltage and is connected to the input terminal of the charge pump. The output terminal of the charge pump is connected to the gate of the MOSFET. The voltage sampling circuit samples the output voltage of the main drive circuit. The signal output terminal of the voltage sampling circuit is connected to the input terminal of the comparison module to input the voltage sample value. The comparison module is connected to the control terminals of the main drive circuit and the backup drive circuit. The output terminal of the backup drive circuit is connected to the input terminal of the charge pump. The comparison module compares the voltage sample value with an upper voltage limit and a lower voltage limit, and controls the outputs of the main drive circuit and the backup drive circuit based on the comparison result. Specifically, when the voltage sample value is higher than the upper voltage limit, the comparison module shuts down the output of the main drive circuit; when the voltage sample value is lower than the upper voltage limit but higher than the lower voltage limit, the comparison module maintains the output of the main drive circuit and shuts down the output of the backup drive circuit; when the voltage sample value is lower than the lower voltage limit, the comparison module maintains the output of the main drive circuit and turns on the output of the backup drive circuit to increase the input voltage of the charge pump.

[0006] According to some embodiments of this application, the backup drive circuit includes a backup drive power supply and a first capacitor. The comparison module is connected to the control terminal of the backup drive power supply, and the output terminal of the backup drive power supply is connected to the input terminal of the charge pump through the first capacitor.

[0007] According to some embodiments of this application, the backup drive circuit further includes a second capacitor, and the input terminal of the charge pump is grounded through the second capacitor.

[0008] According to some embodiments of this application, the comparison module includes a first comparator and a second comparator. The signal output terminal of the voltage sampling circuit is connected to one input terminal of the first comparator and the second comparator, respectively. The other input terminal of the first comparator is used to input the upper limit value of the voltage. The output terminal of the first comparator is connected to the control terminal of the main drive circuit. The other input terminal of the second comparator is used to input the lower limit value of the voltage. The output terminal of the second comparator is connected to the control terminal of the backup drive circuit.

[0009] A power module according to a second aspect embodiment of this application includes a gate drive voltage control circuit as described in the first aspect embodiment.

[0010] The vehicle according to a third aspect embodiment of this application includes a power module as described in the second aspect embodiment.

[0011] The gate drive voltage control circuit, power module, and vehicle according to the embodiments of this application have at least the following beneficial effects: In this embodiment, the drive enable voltage provided by the main drive circuit is boosted by the charge pump and input to the gate of the MOSFET. The comparator module obtains the voltage sample value of the main drive circuit through the voltage sampling circuit and compares the voltage sample value with the upper and lower voltage limits. Under high voltage conditions, if the comparator module detects that the voltage sample value is higher than the upper voltage limit, it shuts off the output of the main drive circuit to turn off the input voltage of the charge pump, thus preventing damage to the MOSFET. Under low voltage conditions, if the comparator module detects that the voltage sample value is lower than the lower voltage limit, it maintains the output of the main drive circuit and turns on the output of the backup drive circuit. The input voltage of the charge pump is increased by superimposing the backup drive voltage and the main drive voltage, thereby reaching the drive voltage threshold of the MOSFET and ensuring normal conduction of the MOSFET. This application can adapt well to both low-voltage and high-voltage conditions and has high reliability.

[0012] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0013] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a schematic block diagram of the gate drive voltage control circuit in the embodiments of this application. Detailed Implementation

[0014] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0015] In the description of this application, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0016] In the description of this application, "multiple" refers to two or more. The use of "first" and "second" is for the purpose of distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of technical features indicated, or the order in which the technical features are indicated.

[0017] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0018] Reference Figure 1 As shown, a gate drive voltage control circuit includes: The power supply unit includes a power supply and a MOSFET. The power supply is connected to the drain of the MOSFET, and the source of the MOSFET is used to connect to the peripheral load. The control unit includes a main drive circuit, a backup drive circuit, a comparison module, a voltage sampling circuit, and a charge pump. The main drive circuit provides the drive enable voltage and is connected to the input of the charge pump. The output of the charge pump is connected to the gate of the MOSFET. The voltage sampling circuit samples the output voltage of the main drive circuit and its signal output is connected to the input of the comparison module for inputting the sampled voltage value. The comparison module is connected to the control terminals of both the main drive circuit and the backup drive circuit. The output of the backup drive circuit is connected to the input of the charge pump. The comparison module compares the sampled voltage value with the upper and lower voltage limits and controls the outputs of the main drive circuit and the backup drive circuit based on the comparison results. Specifically, when the voltage sample value is higher than the upper voltage limit, the comparison module shuts down the output of the main drive circuit; when the voltage sample value is lower than the upper voltage limit but higher than the lower voltage limit, the comparison module maintains the output of the main drive circuit and shuts down the output of the backup drive circuit; when the voltage sample value is lower than the lower voltage limit, the comparison module maintains the output of the main drive circuit and turns on the output of the backup drive circuit to increase the input voltage of the charge pump.

[0019] In this embodiment, the drive enable voltage provided by the main drive circuit is boosted by the charge pump and input to the gate of the MOSFET. The comparator module obtains the voltage sample value of the main drive circuit through the voltage sampling circuit and compares the voltage sample value with the upper and lower voltage limits. Under high voltage conditions, if the comparator module detects that the voltage sample value is higher than the upper voltage limit, it shuts off the output of the main drive circuit to turn off the input voltage of the charge pump, thus preventing damage to the MOSFET. Under low voltage conditions, if the comparator module detects that the voltage sample value is lower than the lower voltage limit, it maintains the output of the main drive circuit and turns on the output of the backup drive circuit. The input voltage of the charge pump is increased by superimposing the backup drive voltage and the main drive voltage, thereby reaching the drive voltage threshold of the MOSFET and ensuring normal conduction of the MOSFET. This application can adapt well to both low-voltage and high-voltage conditions and has high reliability.

[0020] Specifically, in this embodiment, the power supply unit refers to the circuit that provides working power. The power supply is connected to the peripheral load through a MOSFET. When the gate voltage of the MOSFET reaches the conduction threshold, the MOSFET is turned on, and the power supply provides power to the peripheral load. When the gate voltage of the MOSFET is lower than the conduction threshold, the MOSFET is turned off, and the connection between the power supply and the peripheral load is cut off, and the power supply stops.

[0021] It should be understood that in this embodiment, the main drive circuit provides the drive enable voltage. The main drive circuit may include a main drive power supply that provides the drive enable voltage and peripheral circuits. The main drive power supply and the power supply may be the same or different power supplies. Under normal circumstances, the drive enable voltage provided by the main drive circuit is input to the charge pump. After being boosted by the charge pump, it is input to the gate of the MOSFET to reach the turn-on threshold, thereby controlling the MOSFET to turn on.

[0022] This implementation uses a voltage sampling circuit to acquire the voltage sample value of the main drive circuit and input it into a comparison module. The comparison module compares the current voltage sample value with preset upper and lower voltage limits to determine the current operating condition. The upper and lower voltage limits can be preset into the comparison module or reflected by a reference voltage. The upper voltage limit can be considered as the overvoltage shutdown limit, and the lower voltage limit can be considered as the upper limit for extremely low voltage operation. When the voltage sample value is higher than the upper voltage limit, that is, the output voltage of the main drive circuit exceeds the overvoltage shutdown limit, it is in a high-voltage condition. The comparison module shuts down the output of the main drive circuit to prevent the MOSFET from burning out. It should be understood that the backup drive circuit is also obviously in a closed state at this time, with no output voltage. When the voltage sample value is lower than the upper voltage limit but higher than the lower voltage limit, it is in a normal operating condition. That is, the output voltage of the main drive circuit, after being boosted by the voltage pump, can reach the gate conduction threshold of the MOSFET. Therefore, the comparison module maintains the output of the main drive circuit and keeps the backup drive circuit in a closed state. When the voltage sampling value is lower than the lower voltage limit, that is, when the voltage sampling value is lower than the upper limit of the extremely low voltage condition, the output voltage of the main drive circuit cannot reach the gate conduction threshold of the MOSFET even after being boosted by the voltage pump. At this time, it is in a low voltage condition. The comparator module turns on the backup drive circuit and inputs the backup drive module enable signal. At this time, the drive enable and backup drive enable are output simultaneously, increasing the input voltage of the charge pump so that the output voltage of the charge pump reaches the gate conduction threshold of the MOSFET.

[0023] It should be noted that the comparison module in this application can be a comparator or a power control chip with logic judgment function. When a comparator is used, two reference voltage sources with different voltage values ​​are input to the comparator, which are used as the upper and lower voltage limits respectively, and compared with the voltage sample value. When a power control chip is used, the upper and lower voltage limits and the voltage sample value are set as preset values ​​in the chip's built-in program.

[0024] In summary, this application maintains stable MOSFET operation even under low-voltage drive input conditions, thanks to the voltage boosted by the charge pump; under high-voltage conditions, the drive unit can be quickly turned off. By dynamically monitoring the output voltage of the main drive circuit, when the voltage drops below a certain value, the backup drive circuit is activated to boost the charge pump input voltage, increasing the gate drive voltage and ensuring stable MOSFET conduction; when the voltage exceeds the normal operating voltage, the drive voltage is turned off to prevent MOSFET damage. This achieves adaptive adjustment of the gate drive voltage.

[0025] In some implementations, the backup drive circuit includes a backup drive power supply and a first capacitor C1. The comparison module is connected to the control terminal of the backup drive power supply, and the output terminal of the backup drive power supply is connected to the input terminal of the charge pump through the first capacitor C1.

[0026] Specifically, in this embodiment, the backup drive enable is a PWM signal. The comparison module controls the backup drive circuit to continuously charge the first capacitor C1, and after raising the voltage of the first capacitor C1, it is input to the charge pump to increase the input voltage of the charge pump.

[0027] In some implementations, the backup drive circuit also includes a second capacitor C2, through which the input of the charge pump is grounded.

[0028] In this embodiment, in order to obtain a stable voltage value, the voltage of the first capacitor C1 is filtered by the second capacitor C2 and then output to the charge pump, which can further improve the stability of the circuit.

[0029] In some implementations, the comparison module includes a first comparator and a second comparator. The signal output terminal of the voltage sampling circuit is connected to one input terminal of the first comparator and the second comparator, respectively. The other input terminal of the first comparator is used to input the upper limit value of the voltage. The output terminal of the first comparator is connected to the control terminal of the main drive circuit. The other input terminal of the second comparator is used to input the lower limit value of the voltage. The output terminal of the second comparator is connected to the control terminal of the standby drive circuit.

[0030] Specifically, this embodiment uses two comparators to form a comparison module. The first reference source provides the upper voltage limit value, which is connected to the non-inverting input of the first comparator. The signal output of the voltage sampling circuit is connected to the inverting input of the first comparator. Under normal operating conditions, the upper voltage limit value is higher than the voltage sampling value, and the first comparator outputs a high level to keep the main drive circuit working normally. Under high voltage conditions, the voltage sampling value is higher than the upper voltage limit value, and the first comparator outputs a low level to stop the output of the main drive circuit. The signal output of the voltage sampling circuit is connected to the inverting input of the second comparator, and the second reference source provides the lower voltage limit value, which is connected to the non-inverting input of the second comparator. Under normal operating conditions, the voltage sampling value is higher than the lower voltage limit value, and the second comparator outputs a low level, keeping the backup drive circuit off. Under low voltage conditions, the voltage sampling value is lower than the lower voltage limit value, and the second comparator outputs a high level, keeping the backup drive circuit active and outputting a backup drive voltage to the charge pump.

[0031] The following uses the left and right adjustment function of the rearview mirror in a vehicle as an example to explain in detail the working process of this application: The vehicle's left and right rearview mirrors must be able to operate normally within the vehicle battery voltage range of 6V-18V. Figure 1 The power supply and main drive circuit are both based on the battery voltage, which means the drive enable signal is also based on the battery voltage. When the MOSFET is turned on, the source voltage and drain voltage of the MOSFET are basically the same. At this time, the gate voltage VGS is less than the gate threshold voltage VGS(th), and the MOSFET is turned off. In order to ensure that the MOSFET is turned on stably, the drive enable voltage is raised to nearly twice by a charge pump to drive the peripheral load to work.

[0032] The voltage sampling circuit uses a high-precision sampling resistor to acquire the drive enable voltage. The sampled voltage value is sent to the comparison module. The comparison reference voltages are set to an upper limit of 18V and a lower limit of 8V. When the voltage is higher than 18V, the comparison module outputs an interrupt signal to turn off the drive enable and protect the MOSFET; when the voltage is lower than 8V, the comparison module outputs an enable signal to start the backup drive circuit.

[0033] The standby drive signal output is a PWM signal with the same voltage value as the drive enable voltage, with a duty cycle of 50%. The first capacitor C1 and the second capacitor C2 are both 220nF capacitors. When the drive enable voltage is 8V and the standby drive voltage is 0V, the voltage at one end of the first capacitor C1 is 8V and the voltage at the other end is 0V. At this time, the charge pump input voltage is 8V. When both the drive enable voltage and the standby drive voltage are 8V, the characteristics of the capacitor ensure that the voltage at both ends of the first capacitor C1 is 8V. At this time, the charge pump input voltage is 16V. Since the duty cycle is 50%, the charge pump input voltage is between 8V and 16V. After being filtered by the second capacitor C2, it is input to the charge pump. At this time, the voltage value is boosted to the 12-16V range. After being boosted by the charge pump, VGS is greater than VGS(th), ensuring that the MOSFET is stably turned on.

[0034] This application also relates to a power module, including the gate drive voltage control circuit of the above embodiments.

[0035] Specifically, the power module can supply power to the electrical equipment in the vehicle, such as the interior lights, the left and right rearview mirrors, the vehicle domain controller, and other peripherals.

[0036] This application also relates to a vehicle that includes the power module described in the above embodiments.

[0037] In this embodiment, the vehicle can be a private car, such as a sedan, SUV, MPV, or pickup truck. The vehicle can also be a commercial vehicle, such as a van, bus, small truck, or large semi-trailer. The vehicle can be a gasoline-powered vehicle or a new energy vehicle. When the vehicle is a new energy vehicle, it can be a hybrid vehicle or a pure electric vehicle.

[0038] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application.

Claims

1. A gate drive voltage control circuit, characterized by, The application relates to a gate drive voltage control circuit. The application relates to a power supply module. The application relates to a gate drive voltage control circuit. The application relates to a power supply module.

2. The gate drive voltage control circuit of claim 1, wherein, ​ 3. The gate drive voltage control circuit of claim 2, wherein, ​ 4. The gate drive voltage control circuit of claim 1, wherein, ​ 5. A power module, characterized by ​ 6. A vehicle characterized by comprising: ​

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