CN117215362A

CN117215362A - Overshoot protection circuit, voltage stabilizer, chip and electronic equipment

Info

Publication number: CN117215362A
Application number: CN202311262150.5A
Authority: CN
Inventors: 刘贝贝; 何文明
Original assignee: Shenzhen Pango Microsystems Co Ltd
Current assignee: Shenzhen Pango Microsystems Co Ltd
Priority date: 2023-09-27
Filing date: 2023-09-27
Publication date: 2023-12-12

Abstract

The application provides an overshoot protection circuit, a voltage stabilizer, a chip and electronic equipment, wherein the circuit comprises: the overshoot protection circuit is applied to the power module, and the overshoot protection circuit comprises an overshoot protection module and a selection module, wherein: the overshoot protection module is used for receiving the output voltage of the power supply module, generating an overshoot voltage or an undershoot voltage when the load changes, starting the overshoot protection circuit to work, and outputting a control signal when the voltage is outside a preset load voltage range; the selection module opens the corresponding switch tube through the overshoot voltage or undershoot voltage generated by the power supply module during load transient, charges or discharges the LDO grid capacitor, and optimizes the transient performance of the LDO. The application limits the overshoot voltage and the undershoot voltage generated by the power supply module at the moment of load switching to a given voltage range, controls the magnitude of the peak voltage at any moment of load switching of the power supply module, and avoids generating larger peak voltage.

Description

Overshoot protection circuit, voltage stabilizer, chip and electronic equipment

Technical Field

The present application relates to the field of circuit technologies, and in particular, to an overshoot protection circuit, a voltage regulator, a chip, and an electronic device.

Background

The low dropout linear regulator (Low Dropout Regulator, LDO for short) is widely used in chip design due to its high accuracy, high efficiency, low power consumption, stable output, etc. However, at the moment of switching the LDO load, the current generated by the power tube is unequal to the load current due to the fact that the power tube cannot timely respond to the change of the load, so that larger peak voltage (the peak voltage comprises an overshoot voltage and an undershoot voltage) is caused, the overshoot problem caused by switching the load current only reduces the peak voltage by increasing the load capacitance, but a large amount of load capacitance consumes the area of a chip; moreover, the method of alleviating the overshoot voltage by the load capacitor cannot effectively control the maximum deflectable range of the output voltage, and if the LDO is at the load switching moment, the excessive overshoot voltage can cause the chip to reset or damage the chip.

Disclosure of Invention

The application provides an overshoot protection circuit, a voltage stabilizer, a chip and electronic equipment, which mainly aim to protect a power module, prevent spike voltage generated at the moment of switching load current and avoid damage of the power module.

In a first aspect, an embodiment of the present application provides an overshoot protection circuit, where the overshoot protection circuit is applied to a power supply module, and the overshoot protection circuit includes an overshoot protection module and a selection module, where:

the overshoot protection module is used for detecting the output voltage of the power supply module and outputting a control signal when the output voltage is out of a preset voltage range;

and the selection module is used for enabling the parasitic capacitance of the first power tube in the power supply module to charge or discharge according to the control signal when the output voltage is out of the preset voltage range, so that the power supply module outputs peak voltage caused by optimizing load switching.

Further, the preset voltage range includes a preset highest voltage threshold and a preset lowest voltage threshold, and the control signal includes a first control signal and a second control signal, wherein:

the overshoot protection module is used for outputting the first control signal when the output voltage is greater than the preset maximum voltage threshold value, and outputting the second control signal when the output voltage is less than the preset minimum voltage threshold value;

the selection module is used for controlling the parasitic capacitance to charge according to the first control signal and controlling the parasitic capacitance to discharge according to the second control signal.

Further, the overshoot protection module includes an overvoltage detection unit and an undervoltage detection unit, wherein:

the overvoltage detection unit comprises a second power tube, and is used for outputting a first comparison signal when the output voltage is larger than a preset maximum voltage threshold value, and controlling the second power tube to output a first control signal according to the first comparison signal;

the undervoltage detection unit comprises a third power tube, and is used for outputting a second comparison signal when the output voltage is smaller than a preset minimum voltage threshold value, and controlling the third power tube to output a second control signal according to the second comparison signal.

Further, the overvoltage detection unit comprises a first comparator, the input end of the first comparator is used for being connected with the output end of the power supply module, the output end of the first comparator is connected with the second power tube, the second power tube is used for being connected with an external power supply, and the second power tube outputs the first control signal.

Further, the under-voltage detection unit comprises a second comparator, the input end of the second comparator is used for being connected with the output end of the power supply module, the output end of the second comparator is connected with the third power tube, the third power tube is used for being grounded, and the third power tube outputs the second control signal.

Further, the control module is used for performing an exclusive nor operation on the first comparison signal and the second comparison signal, and outputting the selection signal.

In a second aspect, an embodiment of the present application provides a voltage regulator, including an overshoot protection circuit as provided in the first aspect.

In a third aspect, embodiments of the present application provide a chip comprising an overshoot protection circuit as provided in the first aspect, or a voltage regulator as provided in the second aspect.

In a fourth aspect, an embodiment of the present application provides an electronic device, including an overshoot protection circuit as provided in the first aspect, or a voltage regulator as provided in the second aspect, or a chip as provided in the third aspect.

According to the overshoot protection circuit, the voltage stabilizer, the chip and the electronic equipment, when the output voltage of the power supply module is out of the preset voltage range, the overshoot protection module controls parasitic capacitance in the first power tube in the power supply module to charge or discharge according to the control signal corresponding to the output voltage, so that the condition of overvoltage or undervoltage of the output voltage is slowed down, and the first power tube can timely react at the moment that the load current of the output end of the power supply module is transient, and transient characteristics are improved. The output voltage of the power supply module is within the preset voltage range, the overshoot voltage and undershoot voltage generated by the power supply module due to the output at the moment of load switching are successfully limited within the given voltage range, and the magnitudes of the overshoot voltage and the undershoot voltage can be controlled at any extremely short time of the load switching of the power supply module, so that overshoot is avoided; and without requiring a substantial increase in chip area.

Drawings

FIG. 1 is a circuit diagram of a voltage regulator according to the prior art;

FIG. 2 is a schematic diagram of a prior art load current switching from light load to heavy load;

FIG. 3 is a schematic diagram of a prior art load current switching from heavy load to light load;

fig. 4 is a schematic structural diagram of an overshoot protection circuit according to an embodiment of the present application;

fig. 5 is a circuit diagram of an overshoot protection module according to an embodiment of the present application;

fig. 6 is a schematic diagram of an overshoot protection circuit according to an embodiment of the present application;

fig. 7 is a circuit diagram of a control module according to an embodiment of the present application;

fig. 8 is a circuit diagram of an overshoot protection circuit applied to a voltage regulator according to an embodiment of the present application;

FIG. 9 is a diagram showing the simulation results of the LDO with and without the overshoot protection circuit when the load is switched from light load to heavy load according to the embodiment of the present application;

fig. 10 is a comparison diagram of simulation results of an LDO with and without an overshoot protection circuit added when a load is switched from a heavy load to a light load in an embodiment of the present application.

Reference numerals:

110, an overshoot protection module; 120, selecting a module;

111, an overpressure detection unit; 112, an under-voltage detection unit;

113, a first comparator; 114, a second comparator;

130, a control module; q1, a first power tube;

q2, a second power tube; q3, a third power tube;

100, overshoot protection circuit.

The achievement of the objects, functional features and advantages of the present application will be further described with reference to the accompanying drawings, in conjunction with the embodiments.

Detailed Description

Embodiments of the present application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are exemplary only for explaining the present application and are not to be construed as limiting the present application.

In order to enable those skilled in the art to better understand the solution of the present application, the following description will make clear and complete descriptions of the technical solution of the present application in the embodiments of the present application with reference to the accompanying drawings. It will be apparent that the described embodiments are only some, but not all, embodiments of the application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

In the embodiment of the application, at least one refers to one or more; plural means two or more. In the description of the present application, the words "first," "second," "third," and the like are used solely for the purpose of distinguishing between descriptions and not necessarily for the purpose of indicating or implying a relative importance or order. Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Reference in the specification to "one embodiment" or "some embodiments" or the like means that a particular feature, structure, or characteristic described in connection with the embodiment is included in one or more embodiments of the application. Thus, the terms "comprising," "including," "having," and variations thereof herein mean "including but not limited to," unless expressly specified otherwise.

It should be noted that in embodiments of the present application, "connected" may be understood as electrically connected, and two electrical components may be connected directly or indirectly between the two electrical components. For example, a may be directly connected to B, or indirectly connected to B via one or more other electrical components.

In the voltage stabilizer provided by the prior art, as shown in fig. 1, VDD represents a power supply, EA represents an error amplifier, MPOW represents a power tube, VREF represents a reference voltage, RFB1 and RFB2 both represent resistors, RL represents a load resistor, CL represents a load capacitor, and V _OUT Representing an output voltage; the voltage stabilizer comprises error amplifierThe feedback network composed of the amplifier, the power tube, the resistor RFB1 and the resistor RFB2 and the output load are composed, and for the voltage stabilizer in the balanced state, the current generated by the power tube is equal to the load current, and the voltage stabilizer outputs the voltage V _OUT And (3) stability.

However, at the moment of switching the load of the voltage stabilizer, the parasitic capacitance exists in the power tube, so that the power tube cannot respond to the change of the load in time, and the current generated by the power tube is unequal to the load current. In the prior art, when the load current is switched from light load to heavy load, as shown in fig. 2, according to kirchhoff current law, the current I generated by the power tube _DS,MPOW Less than the load current I at that time _LOAD The load capacitor CL is balanced by discharging, and the charge accumulated before the capacitor CL is instantaneously discharged, and the discharge current is Δi _OUT ＝|I _DS,POW -I _LOAD I, resulting in an output voltage V _OUT Is pulled low, creating an under-voltage condition.

In the prior art, when the load current is switched from heavy load to light load, as shown in fig. 3, according to kirchhoff current law, the current I generated by the power tube _DS,MPOW Load current I greater than this _LOAD The load capacitor CL starts to charge, at this time, the charge of the capacitor CL starts to accumulate, and the discharge current is Δi _OUT ＝|I _DS,POW -I _LOAD I, output voltage V _OUT Is momentarily lifted, creating an overpressure condition.

In view of the above situation, as shown in fig. 4, an overshoot protection circuit 100 provided in an embodiment of the present application, the overshoot protection circuit 100 is applied to a power module, the overshoot protection circuit 100 includes an overshoot protection module 110 and a selection module 120, where:

the overshoot protection module 110 is configured to detect an output voltage output by the power supply module, and output a control signal when the output voltage is outside a preset voltage range;

the selection module 120 is configured to charge or discharge a parasitic capacitor of the first power tube Q1 in the power module according to the control signal when the output voltage is outside the preset voltage range, so that the power module outputs a spike voltage caused by optimizing load switching.

The overshoot protection circuit 100 in the embodiment of the present application is applied to a power module, where the power module includes an LDO, a charge pump, a DC-DC, etc., and the overshoot protection circuit can be applied to the peak voltage problem caused by load switching of the power module, where the power module can be determined according to the actual situation, and in the embodiment of the present application, the voltage regulator 200 is exemplified as the power module.

In the embodiment of the present application, the overshoot protection circuit 100 includes an overshoot protection module 110 and a selection module 120, wherein an input end of the overshoot protection module 110 is connected to an output end of the voltage regulator 200, an output end of the overshoot protection module 110 is connected to an input end of the selection module 120, and an output end of the selection module 120 is connected to an input end of the voltage regulator 200.

In the process of operating the overshoot protection circuit 100, the voltage regulator 200 outputs an output voltage during operation, generally, the output voltage is an analog voltage signal, and when the overshoot protection module 110 receives the output voltage signal and the voltage regulator 200 generates a large peak voltage (the peak voltage includes an overshoot voltage and an undershoot voltage), the overshoot protection circuit 100 is triggered to start to operate, and a corresponding switching tube is opened according to the type of the peak voltage, so as to generate a charge-discharge path to the gate capacitor of the power tube, thereby compensating the response rate of the power tube during rapid switching due to the load current.

Specifically, the overshoot protection module 110 determines whether the output voltage is within a preset voltage range, where the preset voltage range is a voltage range where the output voltage is stable, that is, a range where the output voltage of the voltage stabilizer 200 is output under the condition that no overvoltage or undervoltage occurs, where the specific value can be determined according to the actual situation, and the embodiment of the present application can be determined according to the actual situation.

When the load current of the voltage regulator 200 suddenly changes, the output voltage outputted by the voltage regulator 200 will also suddenly change from light load to heavy load or from heavy load to light load, if the overshoot detection module 110 determines that the output voltage is outside the preset voltage range, this indicates that the voltage regulator 200 has an overvoltage or undervoltage condition, in order to avoid the overshoot problem, the overshoot protection module 110 outputs a control signal under this condition, typically, the control signal is a digital signal, and the value is 0 or 1, which can be specifically determined according to the actual situation, which is not specifically limited in the embodiment of the present application.

It should be noted that, in the embodiment of the present application, the overshoot protection module 110 may be a circuit formed by a resistor, a capacitor, etc. according to a certain rule, or may be implemented by programming a processor, which may be specifically determined according to an actual situation, which is not specifically limited in the embodiment of the present application.

When the selection module 120 also detects that the output voltage is outside the preset voltage range, the selection module 120 receives the control signal, controls the first power tube Q1 according to the control signal, and provides an additional charge-discharge path to enhance the response rate of the first power tube Q1, so as to prevent the peak voltage problem (the peak voltage includes the overshoot voltage and the undershoot voltage) generated in the load switching process of the LDO, and improve or optimize the transient characteristic of the circuit of the voltage regulator 200.

Generally, the optimized load voltage is within the preset voltage range, and no voltage overshoot problem occurs. The selection module 120 in the embodiment of the present application may be a circuit formed by resistors, capacitors, etc. according to a certain rule, or may be implemented by programming a processor, which may be specifically determined according to actual situations, which is not specifically limited in the embodiment of the present application.

The application successfully controls the peak voltage of the low dropout linear regulator 200 caused by load switching within the threshold range of the LDO output stable voltage, thereby avoiding the influence of larger peak voltage on the performance of the chip.

According to the overshoot protection circuit 100 provided by the application, when the output voltage output by the power supply module is out of the preset voltage range, the overshoot protection module 110 generates a control signal according to the LDO output voltage, the selection module 120 controls the parasitic capacitance in the first power tube Q1 in the power supply module to charge or discharge according to the control signal, and the overshoot protection circuit improves the transient performance of the first power tube by providing an additional charge-discharge path, so that the problem that the power tube cannot respond in time due to the rapid switching of the load current is solved.

The optimal load voltage finally output by the power supply module is within the preset voltage range, the overshoot voltage and undershoot voltage generated by the power supply module output at the moment of load switching are successfully limited within the given voltage range, and the magnitudes of the overshoot voltage and the undershoot voltage can be controlled at any moment of load switching of the power supply module, so that overshoot is avoided; and without requiring a substantial increase in chip area.

In some embodiments, the preset voltage range includes a preset maximum voltage threshold and a preset minimum voltage threshold, and the control signal includes a first control signal and a second control signal, wherein:

the overshoot protection module 110 is configured to output the first control signal when the output voltage is greater than the preset maximum voltage threshold, and output the second control signal when the output voltage is less than the preset minimum voltage threshold;

the selection module 120 is configured to control the parasitic capacitor to charge according to the first control signal, and control the parasitic capacitor to discharge according to the second control signal.

In the embodiment of the present application, two end points of the preset voltage range are a preset highest voltage threshold and a preset lowest voltage threshold, which are respectively represented by VREFMAX and VREFMIN, where the preset highest voltage threshold represents a maximum value that can be reached by the output voltage of the voltage regulator 200 when the voltage regulator 200 works normally, and the preset lowest voltage threshold represents a value that can be reached by the lowest output voltage of the voltage regulator 200 when the voltage regulator works normally, and the specific value can be determined according to practical situations, and the embodiment of the present application is not limited in this way.

After receiving the output voltage, the overshoot protection circuit 100 compares the output voltage with a preset maximum voltage threshold, and if the output voltage is greater than the preset maximum voltage threshold, which indicates that the voltage regulator 200 has an overvoltage condition, the overshoot protection circuit 100 outputs a first control signal; after receiving the first control signal, the selection module 120 controls the first power tube Q1 to be turned on, so that parasitic capacitance in the first power tube Q1 can be charged. When the voltage regulator 200 is over-voltage, the parasitic capacitance in the first power tube Q1 is charged in the embodiment of the application, so as to slow down the trend of the output voltage to continue to be larger, thereby relieving the over-voltage condition of the voltage regulator 200.

Comparing the output voltage with a preset minimum voltage threshold if the output voltage of the voltage regulator 200 is smaller than the preset maximum voltage threshold, and outputting a second control signal by the overshoot protection module 110 if the output voltage is smaller than the preset minimum voltage threshold, which indicates that the voltage regulator has an under-voltage condition; after receiving the second control signal, the selection module 120 controls the first power tube Q1 to be turned on, so that the parasitic capacitance in the first power tube Q1 is discharged. When the voltage regulator 200 is under voltage, the parasitic capacitance in the first power tube Q1 is discharged in the embodiment of the application, so that the output voltage is slowed down and continuously reduced, and the under voltage condition of the voltage regulator 200 is relieved.

If the output voltage is less than the preset maximum voltage threshold and greater than the preset minimum voltage threshold, indicating that the voltage regulator is operating properly, the overshoot protection module 110 is turned off.

It should be noted that, in the embodiment of the present application, the first power transistor Q1 includes a triode and a MOS transistor, which may be specifically determined according to an actual circuit, and the embodiment of the present application is not limited in particular.

As an embodiment, the overshoot protection module 110 includes an overvoltage detection unit 111 and an undervoltage detection unit 112, wherein:

the overvoltage detection unit 111 includes a second power tube Q2, where the overvoltage detection unit 111 is configured to output a first comparison signal when the output voltage is greater than a preset maximum voltage threshold, and control the second power tube Q2 to output a first control signal according to the first comparison signal;

the under-voltage detection unit 112 includes a third power tube Q3, and the under-voltage detection unit 112 is configured to output a second comparison signal when the output voltage is less than a preset minimum voltage threshold, and control the third power tube Q3 to output a second control signal according to the second comparison signal.

In the embodiment of the present application, the overshoot protection module 110 includes an overvoltage detection unit 111 and an undervoltage detection unit 112, where the output end of the power module is connected to the input ends of the overvoltage detection unit 111 and the undervoltage detection unit 112, and the output ends of the overvoltage detection unit 111 and the undervoltage detection unit 112 are both used for outputting control signals, and at most only one unit works at the same time.

The overvoltage detection unit 111 includes a second power tube Q2, the overvoltage detection unit 111 compares the output voltage with a preset maximum voltage threshold, if the output voltage is greater than the preset maximum voltage threshold, a first comparison signal is output, and the second power tube Q2 is controlled to be turned on according to the first comparison signal, so as to output a first control signal with a value, so that the selection module 120 performs a corresponding operation according to the first control signal; if the output voltage is smaller than the preset maximum voltage threshold, another first comparison signal with a value is output, and the second power tube Q2 is controlled to be opened according to the first comparison signal, so that the whole overvoltage detection unit 111 is in an off state.

The under-voltage detection unit 112 includes a third power tube Q3, the under-voltage detection unit 112 compares the output voltage with a preset minimum voltage threshold, if the output voltage is smaller than the preset minimum voltage threshold, a second comparison signal is output, and the third power tube Q3 is controlled to be turned on or off according to the second comparison signal, so as to output a valued second control signal, so that the selection module 120 performs a corresponding operation according to the second control signal; if the output voltage is greater than the preset minimum voltage threshold, another value of the second comparison signal is output, and the third power tube Q3 is controlled to be turned on according to the second comparison signal, so that the whole undervoltage detection unit 112 is in an off state.

It should be noted that, in the embodiment of the present application, the overvoltage detection unit 111 and the undervoltage detection unit 112 may be circuits formed by resistors, capacitors, and the like according to a certain rule, or may be implemented by programming a processor, which may be specifically determined according to actual situations, which is not specifically limited in the embodiment of the present application.

The overvoltage detection unit 111 includes a first comparator 113, an input end of the first comparator 113 is configured to be connected to an output end of the power module, an output end of the first comparator 113 is connected to a control end of the second power tube Q2, a first connection end of the second power tube Q2 is configured to be connected to an external power source, and a second connection end of the second power tube Q2 outputs the first control signal.

For example, the under-voltage detection unit 112 includes a second comparator 114, an input end of the second comparator 114 is configured to be connected to an output end of the power module, an output end of the second comparator 114 is connected to a control end of the third power tube Q3, a first connection end of the third power tube Q3 is configured to be grounded, and a second connection end of the third power tube Q3 outputs the second control signal.

It should be noted that, the second power tube Q2 and the third power tube Q3 may be transistors or MOS tubes, which may be specifically determined according to practical situations, and the embodiment of the present application is not limited in particular.

The embodiment of the application provides an overshoot protection module 110, as shown in fig. 5, in the embodiment of the application, an overvoltage detection unit 111 includes a first comparator 113 and a second power tube Q2, an input end of the first comparator 113 is used for being connected with an output end of a power module, another input end of the first comparator 113 is connected with a first reference signal, the first reference signal is a preset highest voltage threshold, an output end of the first comparator 113 is connected with a control end of the second power tube Q2, a first connection end of the second power tube Q2 is used for being connected with an external power supply, and a second connection end of the second power tube Q2 outputs a first control signal.

The under-voltage detection unit 112 includes a second comparator 114 and a third power tube Q3, where an input end of the second comparator 114 is connected to an output end of the power module, another input end of the second comparator 114 is connected to a second reference signal, the second reference signal is a preset minimum voltage threshold, an output end of the second comparator 114 is connected to a control end of the second power tube Q2, a first connection end of the third power tube Q3 is used for grounding, and a second connection end of the third power tube Q3 outputs a first control signal.

In the embodiment of the application, the second power tube Q2 is a PMOS tube, and the third power tube Q3 is an NMOS tube.

During operation of the overshoot protection module 110, the first and second comparators 113 and 114 receive the output voltage V _OUT The first comparator 113 compares the output voltage with a preset maximum voltage threshold, when the output voltage V _OUT When the voltage is greater than the preset maximum voltage threshold VREFMAX, the first comparator 113 outputs a first comparison signal of 0, the second switch tube is turned on, the first control signal GLITCH_OUT is pulled high, and a parasitic capacitor C from a power supply to the second power tube Q2 is formed _POW,GS Is provided. The first comparator 113 compares the output voltage with a preset minimum voltage threshold, when the output voltage V _OUT Less than a preset minimum voltage threshold V _REFMIN When the second comparator 114 outputs a second comparison signal of 1, the third switch is turned on to pull the second control signal GLITCH_OUT low, forming a parasitic capacitance C of the second power transistor Q2 _POW,GS A discharge path to ground.

In some embodiments, the overshoot protection circuit 100 further includes a control module 130, wherein:

the control module 130 is configured to output a selection signal when the output voltage is outside the preset voltage range, so that the selection module 120 controls the output end of the overshoot protection module 110 to be connected with the first power tube Q1 according to the selection signal.

In the structure of the overshoot protection circuit 100 according to the embodiment of the present application, as shown in fig. 6, the output end of the control module 130 is connected to the control end of the selection module 120, and when the control module 130 determines that the output voltage is outside the preset voltage range, a selection signal is output, specifically, the control module 130 may determine whether the output voltage is outside the preset voltage range by matching the output voltage with the preset voltage range, or may determine that the output voltage is outside the preset voltage range by receiving a certain indication signal, for example, an indication signal received as 0 indicates that the output voltage is within the preset voltage range, and an indication signal received as 1 indicates that the output voltage is outside the preset voltage range; the determination may be specifically performed by actual conditions, which is not specifically limited in the embodiment of the present application.

When the output voltage is outside the preset voltage range, the control module 130 outputs a selection signal, and after the control end of the selection module 120 receives the selection signal, the output end of the overshoot protection module 110 is controlled to be connected with the first power tube Q1, so that the first power tube Q1 is taken over by the overshoot protection module 110 to realize over-voltage or under-voltage adjustment.

It should be noted that, in the embodiment of the present application, the control module 130 may be a circuit formed by resistors, capacitors, and the like according to a certain rule, or may be implemented by programming a processor, which may be specifically determined according to the actual situation, which is not specifically limited in the embodiment of the present application.

As an example, the control module 130 is configured to perform an exclusive nor operation on the first comparison signal and the second comparison signal, and output the selection signal.

In the circuit of the control module 130 provided in the embodiment of the present application, as shown in fig. 7, two input ends of the control module 130 respectively receive a first comparison signal and a second comparison signal, the first comparison signal is represented by CMP1OUT, the second comparison signal is represented by CMP2OUT, and the first comparison signal and the second comparison signal are subjected to exclusive nor operation, when the first comparison signal and the second comparison signal are identical, a selection signal with a size of 1 is output, and when the first comparison signal and the second comparison signal are different, a selection signal with a size of 0 is output, and the selection signal is represented by glitch_enp.

In the embodiment of the present application, the control module 130 is an exclusive or gate, and the first comparison signal and the second comparison signal are respectively connected to two input ends of the exclusive or gate.

It should be noted that the control module 130 further includes a filtering network, which is configured to filter the selection signal and output the filtered selection signal.

In the embodiment of the application, the overshoot protection circuit 100 is applied to a voltage regulator circuit, as shown in fig. 8, and the selection module 120 is a selector 2-1MUX. When the load current is stable, that is, the output voltage of the voltage stabilizer is smaller than the preset maximum voltage threshold VREFMXA and larger than the preset minimum voltage threshold VREFMIN, the first comparator 113 outputs a first control signal of 1, the second comparator 114 outputs a second control signal of 0, the control module 130 performs an exclusive nor operation on the first control signal and the second control signal, and outputs a selection signal glitch_enp of 0, and at this time, the selection module 1202-1MUX selects the output end of the error amplifier to drive the first power tube Q1 of the voltage stabilizer.

When the load current is instantaneously switched from heavy load to light load, the first power tube Q1 is not in reaction, the load capacitor CL starts to charge, resulting in an output voltage V _OUT When the output voltage of the voltage stabilizer is greater than the preset maximum voltage threshold VREFMAX, the first comparator 113 outputs a first comparison signal of 0, the second comparator 114 also outputs a second comparison signal of 0, the control module 130 performs an exclusive nor operation on the first control signal and the second control signal, outputs a selection signal glitch_enp of 1, the first power tube Q1 is turned on, the error amplifier EA is turned off, at this time, the output glitch_out of the overshoot protection circuit 100 is connected with the gate of the first power tube Q1 through 2-1MUX, and the power supply starts to supply power to the gate capacitor C of the first power tube Q1 _GS,POW Charging, resulting in an increase in gate voltage, resulting in a current I generated by the first power transistor Q1 _DS,POW The output voltage is suppressed from increasing, and overshoot is prevented.

When the load current is instantaneously switched from light load to heavy load, the first power tube Q1 is not in reaction, the load capacitor CL begins to discharge, resulting in an output voltage V _OUT When the voltage VOUT is lower than the preset minimum voltage threshold VREFMIN, the first comparator 113 outputs a first comparison signal with a magnitude of 0, the second comparator 114 outputs a second control signal with a magnitude of 1, the error amplifier EA is turned off, the overshoot protection circuit 100 works, and the gate capacitance of the first power transistor Q1 is rapidly discharged, resulting in the current I generated by the first power transistor Q1 _DS,POW The increase of the load capacitor can inhibit the continuous discharge of the load capacitor, the output voltage of the output is not reduced any more, and overshoot is prevented.

As shown in fig. 9, when the output load is switched from light load to heavy load over 64.04ps, the undershoot voltage of the LDO with the overshoot protection circuit at the load switching instant is at least 1.04V, and the undershoot voltage of the LDO without the overshoot protection circuit at the load switching instant is at least 410mV;

as shown in fig. 10, when the output load is switched from heavy load to light load over 64.04ps, the LDO with the overshoot protection circuit generates an overshoot voltage of 2V at the load switching instant at maximum, and the LDO without the overshoot protection circuit generates an overshoot voltage of 2.79V at the load switching instant at maximum.

The lowermost lines in fig. 9 and 10 each represent a current signal.

The embodiment of the present application further provides a voltage regulator 200, where the voltage regulator 200 includes the above-mentioned overcharge protection circuit 100, and the charge protection circuit is applied to the voltage regulator 200, and the specific connection manner thereof may refer to fig. 8.

The embodiment of the application also provides a chip, which comprises the overcharge protection circuit 100, or the voltage stabilizer 200. The Chip (Integrated Circuit, IC) may be, but is not limited to, a SOC (System on Chip) Chip, a SIP (System in Package ) Chip.

The electronic device according to the embodiment of the present application includes a device main body, and the overcharge protection circuit 100, the voltage stabilizer 200, or the chip provided in the device main body. The electronic device may be, but is not limited to, a weight scale, a body fat scale, a nutritional scale, an infrared electronic thermometer, a pulse oximeter, a body composition analyzer, a mobile power supply, a wireless charger, a quick charger, an on-board charger, an adapter, a display, a USB (Universal Serial Bus ) docking station, a stylus, a real wireless headset, an automotive center control screen, an automobile, an intelligent wearable device, a mobile terminal, an intelligent home device. The intelligent wearing equipment comprises, but is not limited to, an intelligent watch, an intelligent bracelet and a cervical vertebra massage instrument. Mobile terminals include, but are not limited to, smartphones, notebook computers, tablet computers, POS (Point of Sales Terminal, point of sale terminal) machines. The intelligent household equipment comprises, but is not limited to, an intelligent socket, an intelligent electric cooker, an intelligent sweeper and an intelligent lamp.

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-described division of the functional units and modules is illustrated, and in practical application, the above-described functional distribution may be performed by different functional units and modules according to needs, i.e. the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-described functions.

The above embodiments are only for illustrating the technical solution of the present application, and not for limiting the same; although the application has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit and scope of the technical solutions of the embodiments of the present application, and are intended to be included in the scope of the present application.

Claims

1. An overshoot protection circuit, wherein the overshoot protection circuit is applied to a power supply module, the overshoot protection circuit comprising an overshoot protection module and a selection module, wherein:

and the selection module is used for enabling the parasitic capacitance of the first power tube in the power supply module to charge or discharge according to the control signal when the output voltage is out of the preset voltage range, so that the power supply module optimizes peak voltage caused by load switching.

2. The overshoot protection circuit of claim 1 wherein the preset voltage range includes a preset maximum voltage threshold and a preset minimum voltage threshold, the control signal including a first control signal and a second control signal, wherein:

3. The overshoot protection circuit of claim 1, wherein the overshoot protection module comprises an over-voltage detection unit and an under-voltage detection unit, wherein:

4. The overshoot protection circuit of claim 3, wherein said over-voltage detection unit comprises a first comparator, an input terminal of said first comparator being connected to an output terminal of said power supply module, an output terminal of said first comparator being connected to said second power tube, said second power tube being connected to an external power supply, said second power tube outputting said first control signal.

5. The overshoot protection circuit of claim 3, wherein said under-voltage detection unit comprises a second comparator, an input terminal of said second comparator is connected to an output terminal of said power supply module, an output terminal of said second comparator is connected to said third power tube, said third power tube is connected to ground, and said third power tube outputs said second control signal.

6. The overshoot protection circuit of any one of claims 1 to 5, further comprising a control module, wherein:

and the control module is used for outputting a selection signal when the output voltage is out of the preset voltage range, so that the selection module controls the output end of the overshoot protection module to be connected with the first power tube according to the selection signal.

7. The overshoot protection circuit of claim 6 wherein the control module is configured to nor the first comparison signal and the second comparison signal to output the selection signal.

8. A voltage regulator to which the overshoot protection circuit according to any one of claims 1 to 7 is applied.

9. A chip comprising an overshoot protection circuit according to any one of claims 1 to 7, or a voltage regulator according to claim 8.

10. An electronic device, comprising:

an overshoot protection circuit according to any one of claims 1 to 7;

or, the voltage stabilizer of claim 8;

or, the chip of claim 9.