CN219760850U

CN219760850U - Drive circuit and power management system

Info

Publication number: CN219760850U
Application number: CN202320309646.2U
Authority: CN
Inventors: 雷云; 张智锋; 林建平
Original assignee: Shenzhen Carku Technology Co Ltd
Current assignee: Shenzhen Carku Technology Co Ltd
Priority date: 2023-02-17
Filing date: 2023-02-17
Publication date: 2023-09-26
Anticipated expiration: 2033-02-17

Abstract

The utility model discloses a driving circuit and a control power management system. The driving circuit comprises a switch driving module and a voltage doubling circuit. The switch driving module is connected with the pulse width modulation end, the reference voltage end and the node and is used for adjusting the voltage of the node according to the pulse width modulation signal of the pulse width modulation end and the voltage of the reference voltage end. The voltage doubling circuit is connected with the source electrode of the switching transistor, the grid electrode of the switching transistor and the node and is used for driving the switching transistor to be conducted according to the output voltage of the power supply and the voltage of the node. Thus, compared with the current driving circuit, the driving circuit provided by the utility model has the advantages of simplifying the structure of the circuit, reducing the cost and being easy for mass production. And the voltage of the node is regulated by setting the switch driving module, so that the allowable voltage range of the positive end of the power supply can be improved, and the problem that the switch transistor is easily damaged due to incomplete starting of the switch transistor caused by the fact that the voltage is larger than a preset threshold value is avoided.

Description

Drive circuit and power management system

Technical Field

The utility model relates to the technical field of drive circuit control, in particular to a drive circuit and a power management system.

Background

In the related art, two main technical schemes are adopted for controlling the positive end of the power supply through the NMOS, one is to drive the positive end of the power supply through the NMOS by adopting a DC-DC isolation power supply, and the other is to drive the positive end of the power supply through the NMOS by adopting a DC-DC booster circuit. However, in the technical scheme of driving the positive end of the source to the NMOS by adopting the DC-DC isolation source, the circuit is complex, the cost is high, and mass production is not facilitated, while the scheme of driving the positive end of the source to the NMOS by adopting the DC-DC boost circuit requires the voltage range of the positive end of the source, and the voltage is larger than the preset threshold value, so that the NMOS control voltage GS is easily caused to be too high, and the NMOS is easily damaged.

Disclosure of Invention

The present utility model aims to solve at least one of the technical problems existing in the prior art. To this end, the present utility model needs to provide a driving circuit and a power management system.

The driving circuit of the embodiment of the utility model is used for a power management system, the power management system comprises a power supply and a switching transistor, the switching transistor is arranged on a positive electrode power supply path of the power supply, the driving circuit is used for controlling the switching transistor to be turned on and off, and the driving circuit comprises:

the switch driving module is connected with the pulse width modulation end, the reference voltage end and the node and is used for adjusting the voltage of the node according to the pulse width modulation signal of the pulse width modulation end and the voltage of the reference voltage end;

and the voltage doubling circuit is connected with the source electrode of the switching transistor, the grid electrode of the switching transistor and the node and is used for driving the switching transistor to be conducted according to the output voltage of the power supply and the voltage of the node.

In some embodiments, the switching transistors include a discharge switching transistor and a charge switching transistor, and the driving circuit includes two driving circuits, one driving circuit is connected to the discharge switching transistor and used for controlling on and off of the discharge switching transistor, and the other driving circuit is connected to the charge switching transistor and used for controlling on and off of the charge switching transistor.

In some embodiments, the switching transistor comprises an NMOS transistor.

In some embodiments, the voltage doubling circuit is configured to generate a second driving voltage according to the voltage of the source and the first driving voltage of the node, and drive the switching transistor to be turned on, where the second driving voltage is positively related to the voltage of the source, and the second driving voltage is greater than the first driving voltage and less than or equal to a sum of the first driving voltage and the voltage of the source.

In some embodiments, the switch driving module includes:

the first connecting end of the first switching tube is connected with the reference voltage end, the second connecting end of the first switching tube is connected with the grounding end, and the control end of the first switching tube is connected with the pulse width modulation end;

the first connecting end of the second switching tube is connected with the reference voltage end, the second connecting end of the second switching tube is connected with the node, and the control end of the second switching tube is connected with the first connecting end of the first switching tube;

and the first connecting end of the third switching tube is connected with the node, the second connecting end of the third switching tube is connected with the grounding end, and the control end of the third switching tube is connected with the first connecting end of the first switching tube.

In certain embodiments, the switch drive module further comprises:

and the positive electrode of the clamping diode is connected with the node, and the negative electrode of the clamping diode is connected with the first connecting end of the second switching tube.

In certain embodiments, the switch drive module further comprises:

one end of the first resistor is connected with the pulse width modulation end, and the other end of the first resistor is connected with the control end of the first switching tube;

and one end of the second resistor is connected with the reference voltage end, and the other end of the second resistor is connected with the first connecting end of the first switching tube, the control end of the second switching tube and the control end of the third switching tube.

In some embodiments, the voltage doubling circuit comprises:

the positive electrode of the first isolation diode is connected with the positive electrode of the power supply;

one end of the energy storage capacitor is connected with the node, and the other end of the energy storage capacitor is connected with the cathode of the first isolation diode;

and the anode of the second isolation diode is connected with the cathode of the first isolation diode and the energy storage capacitor, and the cathode of the second isolation diode is connected with the switching transistor.

In some embodiments, the driving circuit further comprises:

and one end of the voltage stabilizing capacitor is connected with the positive electrode of the power supply, and the other end of the voltage stabilizing capacitor is connected with the negative electrode of the second isolation diode.

In some embodiments, the driving circuit further comprises:

and the turn-off module is respectively connected with the interrupt control end, the grid electrode of the switch transistor and the grounding end and is used for enabling the grid electrode of the switch transistor to be communicated with the grounding end according to the interrupt control signal provided by the interrupt control end so as to turn off the switch transistor.

In certain embodiments, the shutdown module comprises:

one end of the current limiting resistor is connected with the grid electrode of the switching transistor;

and the drain electrode of the control transistor is connected with the other end of the current limiting resistor, the source electrode of the control transistor is connected with the grounding end, and the grid electrode of the control transistor is connected with the interrupt control end.

In some embodiments, the driving circuit further comprises:

one end of the voltage stabilizing module is connected with the source electrode of the switching transistor, and the other end of the voltage stabilizing module is connected with the grid electrode of the switching transistor and used for limiting the voltage difference between the source electrode and the grid electrode of the switching transistor;

and one end of the load resistor is connected with the grid electrode of the switching transistor, and the other end of the load resistor is connected with the source electrode of the switching transistor.

The power management system according to an embodiment of the present utility model includes a power supply, a switching transistor provided in a positive power supply path of the power supply, and the drive circuit according to any one of the above.

In some embodiments, the power management system further comprises a fuse resistor, the fuse resistor being connected to the power source.

In the driving circuit and the power management system according to the embodiments of the present utility model, the switch driving module is connected to the pwm terminal, the reference voltage terminal, and the node, and when the voltage of the node needs to be adjusted, the voltage of the node is adjusted by the pwm signal of the pwm terminal and the voltage of the reference voltage terminal, and the voltage doubling circuit is connected to the positive electrode of the power supply, the gate of the switching transistor, and the node, and when the switching transistor needs to be turned on, the switching transistor is driven to be turned on according to the output voltage of the power supply and the voltage of the node. Thus, compared with the current driving circuit, the driving circuit provided by the utility model has the advantages of simplifying the structure of the circuit, reducing the cost and being easy for mass production. And the voltage of the node is regulated by setting the switch driving module, so that the allowable voltage range of the positive end of the power supply can be improved, and the problem that the switch transistor is easily damaged due to incomplete starting of the switch transistor caused by the fact that the voltage is larger than a preset threshold value is avoided.

Additional aspects and advantages of the utility model 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 the utility model.

Drawings

The foregoing and/or additional aspects and advantages of the present utility model will become apparent and readily appreciated from the following description of the embodiments, taken in conjunction with the accompanying drawings, in which:

fig. 1 is a block diagram of a power management system according to an embodiment of the present utility model.

Fig. 2 is a schematic circuit connection diagram of a power management system according to an embodiment of the present utility model.

Fig. 3 is another schematic circuit connection diagram of the power management system according to the embodiment of the present utility model.

Description of main reference numerals:

a power management system 1000; a driving circuit 100; a switch driving module 10; a voltage doubler circuit 30; a shut-down module 50; a voltage stabilizing module 70;

a pulse modulation control end PWM; a power supply VBAT; a node N; interrupt control end Pulse; a ground GND; a reference voltage terminal U;

a first switching tube Q1; a second switching tube Q2; a third switching tube Q3; a clamp diode D1; a first resistor R1; a second resistor R2; a first voltage V1; a first isolation diode D2; an energy storage capacitor C1; a second isolation diode D3; a second voltage V2; a voltage stabilizing capacitor C2; a third voltage V3; a current limiting resistor R3; a control transistor Q4; a third resistor R4; a first zener diode ZD1; a second zener diode ZD2; a first zener diode ZD1; a second zener diode ZD2; a load resistor R5; a fourth resistor R6; a switching transistor Q5; a discharge switching transistor Q51; a charge switching transistor Q52;

Detailed Description

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

In the description of the present utility model, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. 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 of the described features. In the description of the present utility model, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The following disclosure provides many different embodiments, or examples, for implementing different features of the utility model. In order to simplify the present disclosure, components and arrangements of specific examples are described below. They are, of course, merely examples and are not intended to limit the utility model. Furthermore, the present utility model may repeat reference numerals and/or letters in the various examples, which are for the purpose of brevity and clarity, and which do not themselves indicate the relationship between the various embodiments and/or arrangements discussed. In addition, the present utility model provides examples of various specific processes and materials, but one of ordinary skill in the art will recognize the application of other processes and/or the use of other materials.

In view of this, referring to fig. 1, the present utility model provides a driving circuit 100 for a power management system 1000. The power management system 1000 includes a power supply VBAT and a switching transistor Q5, the switching transistor Q5 is disposed on a positive B power supply path of the power supply VBAT, and the driving circuit 100 is used for controlling the switching transistor Q5 to be turned on and off. The driving circuit 100 includes a switch driving module 10 and a voltage doubler 30.

The switch driving module 10 is connected to the PWM terminal PWM, the reference voltage terminal U, and the node N, respectively. The switch driving module 10 is configured to adjust the voltage of the node N according to the PWM signal of the PWM terminal PWM and the voltage of the reference voltage terminal U. The voltage doubler circuit 30 is connected to the positive electrode B of the power supply VBAT, the gate of the switching transistor Q5, and the node N, respectively. The voltage doubler circuit 30 is used to connect the positive pole B of the power supply VBAT, the gate of the switching transistor Q5, and the node N. It is understood that the arrangement of the off transistor Q5 in the positive B supply path of the power supply VBAT may refer to the switching transistor Q5 in series with the positive B of the power supply VBAT.

In the driving circuit 100 and the power management system 1000 according to the embodiment of the present utility model, the switch driving module 10 is connected to the PWM terminal PWM, the reference voltage terminal U, and the node N, and when the voltage of the node N needs to be adjusted, the voltage of the node N is adjusted by the PWM signal of the PWM terminal PWM and the voltage of the reference voltage terminal U, and the voltage doubler circuit 30 is connected to the positive electrode B of the power supply VBAT, the gate of the switching transistor Q5, and the node N, and when the switching transistor Q5 needs to be turned on, the switching transistor Q5 is driven to be turned on according to the output voltage of the power supply VBAT and the voltage of the node N. Thus, the driving circuit 100 of the present utility model simplifies the circuit structure, reduces the cost, and is easy for mass production compared with the current driving circuit 100. And the voltage of the node N is regulated by setting the switch driving module 10, so that the allowable voltage range of the positive end of the power supply VBAT can be increased, and the problem that the switch transistor Q5 is easily damaged due to incomplete starting of the switch transistor Q5 caused by the fact that the voltage is larger than a preset threshold value is avoided.

In some embodiments, as shown in fig. 3, the switching transistor Q5 includes a discharging switching transistor Q51 and a charging switching transistor Q52. The driving circuit 100 includes two driving circuits 100, wherein one driving circuit 100 is connected to the discharging switch transistor Q51 for controlling the on and off of the discharging switch transistor Q51. The other driving circuit 100 is connected to the charge switch transistor Q52 for controlling the charge switch transistor Q52 to be turned on and off. Note that BAT in fig. 3 represents an output of the power supply VBAT.

In this way, by providing two driving circuits 100, one driving circuit 100 is connected to the discharging transistor, and the other driving circuit 100 is connected to the charging switch transistor Q52, the power management system 1000 has a discharging function while having a specific charging function.

In some embodiments, the switching transistor Q5 comprises an NMOS transistor. Therefore, the switching transistor Q5 can be an NMOS transistor, and the parameter specification of the NMOS transistor is cheaper than that of the PMOS transistor in the same circuit, so that the generation cost can be reduced in actual production.

In some embodiments, the voltage doubling circuit 30 is configured to generate a second driving voltage according to the voltage of the source and the first driving voltage of the node N, and drive the switching transistor Q5 to be turned on, where the second driving voltage is positively related to the voltage of the source, and the second driving voltage is greater than the first driving voltage and less than or equal to the sum of the first driving voltage and the voltage of the source.

The second driving voltage may be less than the sum of the first driving voltage and the voltage of the source, for example, the first driving voltage is 3V, the voltage of the source is 2.5V, and the second driving voltage may be 4V, 4.1V, 4.2V, 4.3V, 4.4V, 4.5V, 4.6V, 4.7V, 4.8V, 4.9V, and 5V, which are not limited herein. The second driving voltage may be equal to a sum of the first driving voltage and a voltage of the source, for example, the first driving voltage is 3.1V, the voltage of the source is 2.9V, and the second driving voltage may be 6V, which is not limited herein.

Specifically, when the second switching transistor Q2 is turned on when it gets a high level, the source of the second switching transistor Q2 generates a voltage, and the node N generates a first driving voltage, and charges the energy storage capacitor C1 with the first driving voltage, so that the energy storage capacitor C1 works to generate a second driving voltage greater than the first driving voltage, and drives the switching transistor Q5 to be turned on through the second driving voltage.

Referring to fig. 2, in some embodiments, the switch driving module 10 includes a first switching tube Q1, a second switching tube Q2, and a third switching tube Q3. The first connecting end of the first switching tube Q1 is connected with the reference voltage end U, the second connecting end is connected with the grounding end GND, and the control end is connected with the pulse width modulation end PWM. The first connecting end of the second switching tube Q2 is connected with the reference voltage end U, the second connecting end is connected with the node N, and the control end is connected with the first connecting end of the first switching tube Q1. The first connecting end of the third switching tube Q3 is connected with the node N, the second connecting end is connected with the grounding end GND, and the control end is connected with the first connecting end of the first switching tube Q1. The first switching tube Q1 is configured to control on or off of the second switching tube Q2 and the first switching tube Q1 according to the pulse width modulation signal when the pulse width modulation signal is received. It is understood that, since the second connection terminal of the second switching tube Q2 is connected to the node N and the first connection terminal of the third switching tube Q3 is also connected to the node N, the second connection terminal of the second switching tube Q2 is connected to the first connection terminal of the third switching tube Q3. V1 represents the first voltage of the node N.

Alternatively, the reference voltage may be a voltage preset in advance, and the reference voltage may be, for example, 12V, 12.1V, 12.2V, 12.3V, 12.4V, 12.5V, 12.6V, 12.7V, 12.8V, 12.9V, and 13V, which are not limited herein.

Alternatively, the first switching tube Q1 and the second switching tube Q2 may be N-type switching tubes, and the third switching tube Q3 may be a P-type switching tube. The control end of the first switching tube Q1 and the control end of the second switching tube Q2 are turned on when receiving a high level, and are turned off when receiving a low level; the control end of the third switching tube Q3 is turned on when receiving the low level, and the control end of the first switching tube Q1 and the control end of the second switching tube Q2 are turned off when receiving the high level. In the N-type transistor, the first connection terminal represents the collector, the second connection terminal represents the emitter, and the control terminal represents the base; in the P-type transistor, the first connection terminal represents the emitter, the second connection terminal represents the collector, and the control terminal represents the base.

Specifically, when the control end of the first switching tube Q1 receives the pwm signal, the first switching tube Q1 is turned from off to on, the control end of the third switching tube Q3 is connected to the first connection end of the first switching tube Q1, the reference voltage end U is connected to the ground end GND to form a potential, and the control end of the second switching tube Q2 is connected to the reference voltage end U, so that at this time, a potential exists at the control end of the second switching tube Q2, the second switching tube Q2 is turned from low level to high level, the second switching tube Q2 is turned from off to on, the control end of the third switching tube Q3 is turned from low level to high level, and the third switching tube Q3 is turned from on to off.

It can be understood that when the PWM terminal PWM stops transmitting the PWM signal, the first switching tube Q1 is turned off, and at this time, the second switching tube Q2 is turned off, the reference voltage terminal U is stopped communicating with the ground terminal GND, the control terminal of the second switching tube Q2 is turned from high level to low level, the second switching tube Q2 is turned from on to off, the control terminal of the third switching tube Q3 is turned from high level to low level, and the third switching tube Q3 is turned from off to on.

In this way, the control end of the first switching tube Q1 is connected with the PWM end, and the first connection end of the first switching tube Q1 is connected with the reference voltage end U, the control end of the second switching tube Q2, and the control end of the third switching tube Q3, so as to control the on or off of the second switching tube Q2 and the third switching tube Q3.

Referring to fig. 2, in some embodiments, the switch driving module 10 further includes a clamping diode D1. The positive electrode of the clamping diode D1 is connected with the node N, and the negative electrode of the clamping diode D1 is connected with the first connecting end of the second switching tube Q2.

It is understood that since the first connection terminal of the second switching tube Q2 is connected to the reference voltage terminal U and the negative electrode of the clamp diode D1 is connected to the first connection terminal of the second switching tube Q2, the negative electrode of the clamp diode D1 is connected to the reference voltage terminal U.

Specifically, when the first voltage V1 of the node N needs to be increased, since the positive electrode of the clamp diode D1 is connected to the node N and the negative electrode of the clamp diode D1 is connected to the first connection terminal of the second switching tube Q2, the first voltage V1 of the node N can be increased by the clamp diode D1.

For example, the reference voltage is 12V, since the negative electrode of the clamp diode D1 is connected to the reference voltage, the voltage of the negative electrode of the clamp diode D1 is 12V at this time, when the clamp diode D1 is turned on and the voltage of the positive electrode of the clamp diode D1 is greater than the voltage of the negative electrode of the clamp diode D1, the voltage across the clamp diode D1 is limited to the voltage drop thereof, and the silicon diode of the clamp diode D1 is about 0.7V, that is, the voltage across the clamp diode D1 is clamped to 0.7V, and the negative electrode of the clamp diode D1 is 12V at this time, the voltage of the positive electrode of the clamp diode D1 is 12.7V, and since the positive electrode of the clamp diode D1 is connected to the node N, the first voltage V1 of the node N is clamped to 12.7V at this time.

In this way, by providing the clamp diode D1 in the switch driving module 10, and connecting the negative electrode of the clamp diode D1 to the reference voltage terminal U, the positive electrode of the clamp diode D1 is connected to the node N, and the first voltage V1 of the node N is clamped to the highest value by the clamp diode D1.

Referring to fig. 2, in some embodiments, the switch driving module 10 further includes a first resistor R1 and a second resistor R2. One end of the first resistor R1 is connected with the pulse width modulation end PWM, and the other end of the first resistor R1 is connected with the control end of the first switching tube Q1. One end of the second resistor R2 is connected with the reference voltage end U, and the other end of the second resistor R2 is connected with the first connecting end of the first switching tube Q1, the control end of the second switching tube Q2 and the control end of the third switching tube Q3.

Alternatively, the first resistor R1 and the second resistor R2 may be constant resistors, which are not limited herein. The resistance values of the first resistor R1 and the second resistor R2 may be preset in advance, and the resistance values of the first resistor R1 and the second resistor R2 may be, for example, 10kΩ, 10.1kΩ, 10.2kΩ, 10.3kΩ, 10.4kΩ, 10.5kΩ, 10.6kΩ, 10.7kΩ, 10.8kΩ, 10.9kΩ, and 11kΩ, which are not limited herein.

It can be understood that, since one end of the second resistor R2 is connected to the reference voltage terminal U and the first end of the second switching tube Q2 is connected to the reference voltage terminal U, the negative electrode of the clamping diode D1 is connected to the first connection end of the second switching tube Q2, so that one end of the second resistor R2 is connected to the first end of the second switching tube Q2 and the negative electrode of the clamping diode D1, respectively, and since the other end of the second resistor R2 is connected to the first connection end of the first switching tube Q1, the control end of the second switching tube Q2 is connected to the control end of the third switching tube Q3, the second switching tube Q2, the third switching tube Q3 and the clamping diode D1 can be protected by the current limiting function of the second resistor R2, so as to prevent the second switching tube Q2, the third switching tube Q3 and the clamping diode D1 from being damaged due to excessive current flowing through them.

It can be further understood that, since one end of the first resistor R1 is connected to the PWM terminal PWM and the other end of the first resistor R1 is connected to the control terminal of the first switching tube Q1, the same current limiting effect of the first resistor R1 can protect the first switching tube Q1 and prevent the first switching tube Q1 from being damaged due to excessive current flowing through the first resistor R1.

In this way, since the first switching tube Q1, the second switching tube Q2, the third switching tube Q3 and the clamp diode D1 are relatively sensitive to the current, and are easily damaged when the current is excessively large, the first resistor R1 and the second resistor R2 are provided in the switch driving module 10, and the current flowing through the first switching tube Q1, the second switching tube Q2, the third switching tube Q3 and the clamp diode D1 can be effectively prevented from being excessively large by the current limiting action of the first resistor R1 and the second resistor R2, thereby preventing the first switching tube Q1, the second switching tube Q2, the third switching tube Q3 and the clamp diode D1 from being damaged by the excessively large current flowing therethrough.

Referring to fig. 2, in some embodiments, the voltage doubler circuit 30 includes a first isolation diode D2, a storage capacitor C1, and a second isolation diode D3. The positive pole of the first isolation diode D2 is connected to the positive pole B of the power supply VBAT. One end of the energy storage capacitor C1 is connected with the node N, and the other end of the energy storage capacitor C is connected with the cathode of the first isolation diode D2. The positive pole of the second isolation diode D3 is connected with the negative pole of the first isolation diode D2 and the energy storage capacitor C1, and the negative pole is connected with the switching transistor Q5.

It can be understood that, since one end of the energy storage capacitor C1 is connected to the node N, and the node N is connected to the second connection end of the second switching tube Q2 and the first connection end of the third switching tube Q3, respectively, one end of the energy storage capacitor C1 is connected to the second connection end of the second switching tube Q2 and the first connection end of the third switching tube Q3, respectively.

As shown in fig. 2, V2 represents a second voltage V2 at the other end of the storage capacitor C1. It is understood that, since the cathode of the first isolation diode D2 is connected to the other end of the energy storage capacitor C1, and the anode of the second isolation diode D3 is connected to the cathode of the first isolation diode D2 and the other end of the energy storage capacitor C1, respectively, the second voltage may also represent the second voltage V2 of the cathode of the first isolation diode D2 and the anode of the second isolation diode D3, respectively.

Note that V3 shown in fig. 2 represents a third voltage between the negative electrode of the second isolation diode D2 and the switching transistor Q5. Specifically, the cathode of the second isolation diode D3 may be connected to the gate of the switching transistor Q5, so V3 also represents a third voltage of the cathode of the second isolation diode D3 and the gate of the switching transistor Q5.

Specifically, when the switching transistor Q5 needs to be turned on, the PWM terminal PWM sends a pulse modulation signal to the control terminal of the first switching transistor Q1, the first switching transistor Q1 is turned on from off, at this time, the reference voltage terminal U is connected to the ground terminal GND to form a potential, because the control terminal of the second switching transistor Q2 is connected to the reference voltage terminal U, the second switching transistor Q2 is turned from low level to high level, at this time, the second switching transistor Q2 is turned on from off, the third switching transistor Q3 is turned from low level to high level, at this time, the third switching transistor Q3 is turned off from on, at this time, the second switching transistor Q2 is turned on, so that the reference voltage terminal U is connected to the energy storage capacitor C1 to charge the energy storage capacitor C1, at this time, both ends of the first and second isolation diodes D2 and D3 are in a state of having a voltage, at this time, the first isolation diodes D2 and the second isolation diodes D3 are turned on, at this time, the second voltage V2 is the output voltage VBAT the first voltage V1, the output voltage V1 is added to the third voltage VBAT, the output voltage V3 is subtracted from the output voltage at the third voltage V1, and at is the third voltage V3 is subtracted from the output voltage at the voltage at 5. If the voltage of the first voltage V1 is 12V and the output voltage of the power supply VBAT is 12V, the second voltage V2 is 24V, the voltage of the third voltage V3 is 23.3V, and it can be seen that the voltage of the third voltage V3 is 11.3V higher than the output voltage of the power supply VBAT, and then the driving switch transistor Q5 is turned on.

In addition, when the pulse width modulation terminal PWM stops sending the pulse modulation signal to the control terminal of the first switching tube Q1, the first switching tube Q1 is turned from on to off, at this time, the second switching tube Q2 is turned off by the first switching tube Q1, the reference voltage terminal U is stopped to be connected to the ground terminal GND, the second switching tube Q2 is turned from high level to low level, at this time, the second switching tube Q2 is turned from on to off, the third switching tube Q3 is turned from high level to low level, and the third switching tube Q3 is turned from off to on, and the second connection terminal of the third switching tube Q3 is connected to the ground terminal GND, so when the third switching tube Q3 is turned on, the energy storage capacitor C1 is connected to the ground terminal GND, and the electric quantity of the energy storage capacitor C1 is consumed due to the connection of the energy storage capacitor C1 to the ground terminal GND, so that the voltage of the energy storage capacitor C1 becomes zero gradually.

In this way, the energy storage and voltage clearing of the energy storage capacitor C1 are controlled by controlling the on or off of the second switching tube Q2 and the third switching tube Q3, so that the switching transistor Q5 is driven to be turned on by the energy storage capacitor C1.

Referring to fig. 2, in some embodiments, the driving circuit 100 further includes a voltage stabilizing capacitor C2. One end of the voltage stabilizing capacitor C2 is connected with the positive pole B of the power supply VBAT, and the other end of the voltage stabilizing capacitor C is connected with the negative pole of the second isolation diode D3.

It is understood that since the other end of the stabilizing capacitor C2 is connected to the negative electrode of the second isolation diode D3, the third voltage V3 represents the voltage between the other end of the stabilizing capacitor C2 and the negative electrode of the second isolation diode D3.

Specifically, since the regulated capacitor C2 has a function of stabilizing the voltage, and the other end of the regulated capacitor C2 is connected to the negative electrode of the second isolation diode D3, the regulated capacitor C2 has a function of stabilizing the voltage of the third voltage V3.

In this way, one end of the voltage stabilizing capacitor C2 is connected to the positive electrode B of the power supply VBAT, and the other end of the voltage stabilizing capacitor C2 is connected to the negative electrode of the second isolation diode D3, so that when the switching transistor Q5 is turned on, the voltage of the third voltage V3 is stabilized, and the switching transistor Q5 is always in a stable on state.

Referring to fig. 2, in some embodiments, the driving circuit 100 further includes a shutdown module 50. The turn-off module 50 is connected to the interrupt control terminal Pulse, the gate of the switching transistor Q5, and the ground terminal GND, respectively. The turn-off module 50 is configured to make the gate of the switching transistor Q5 communicate with the ground GND according to an interrupt control signal provided by the interrupt control terminal Pulse, so as to turn off the switching transistor Q5.

Specifically, when the switching transistor Q5 needs to be turned off, the interrupt control terminal Pulse sends an interrupt control signal to the turn-off module 50, and after the turn-off module 50 receives the interrupt control signal, the turn-off module 50 communicates the gate of the switching transistor Q5 with the ground terminal GND according to the interrupt control signal, thereby controlling the switching transistor Q5 to turn off from on.

In this way, the interrupt control terminal Pulse sends an interrupt control signal to the turn-off module 50, and the turn-off module 50 controls the connection between the switch transistor Q5 and the ground terminal GND according to the interrupt control signal, so that the switch transistor Q5 is controlled to be turned off rapidly when the switch transistor Q5 needs to be turned off.

Referring to fig. 2, in some embodiments, the turn-off module 50 includes a current limiting resistor R3 and a control transistor Q4. One end of the current limiting resistor R3 is connected with the grid electrode of the switching transistor Q5. The drain of the control transistor Q4 is connected to the other end of the current limiting resistor R3, the source is connected to the ground GND, and the gate is connected to the interrupt control terminal Pulse. The control transistor Q4 is configured to be turned on when receiving an interrupt control signal to control the switching transistor Q5 to be turned off. The current limiting resistor R3 is used to limit the current flowing through the control transistor Q4, and prevent the control transistor Q4 from being damaged due to the excessive current flowing through the control transistor Q4.

It is understood that, since one end of the current limiting resistor R3 is connected to the gate of the switching transistor Q5, and the negative electrode of the second isolation diode D3 is connected to the gate of the switching transistor Q5, the third voltage V3 also represents the voltage between one end of the current limiting resistor R3 and the negative electrode of the second isolation diode D3.

Specifically, when the switching transistor Q5 needs to be turned off, since the gate of the control transistor Q4 is connected to the interrupt control terminal Pulse, the source of the control transistor Q4 is connected to the ground terminal GND, the drain of the control transistor Q4 is connected to the other end of the current limiting resistor R3, and since one end of the current limiting resistor R3 is connected to the gate of the switching transistor Q5, when the gate of the control transistor Q4 receives the interrupt control signal sent by the interrupt control terminal Pulse, the control transistor Q4 is turned on from off, and when the control transistor Q4 is turned on, the switching transistor Q5 is turned on with the ground terminal GND, and at this time, the gate of the switching transistor Q5 is turned low from high, and at this time, the switching transistor Q5 is turned off from on because the switching transistor Q5 is turned on at high.

Alternatively, the current limiting resistor R3 may be one or more, which is not limited herein. When the current limiting resistor R3 is one, the current limiting resistor R3 is connected into the shutdown module 50 in a serial mode; when the number of the current limiting resistors R3 is plural, the plural current limiting resistors R3 are connected to the shutdown module 50 in parallel.

Alternatively, the current limiting resistor R3 may be a constant value resistor, which is not limited herein, and the resistance value of the current limiting resistor R3 may be, for example, 470 Ω, 471 Ω, 472 Ω, 473 Ω, 474 Ω, 475 Ω, 476 Ω, 477 Ω, 478 Ω,479 Ω, and 480 Ω, which are not limited herein.

Optionally, the shutdown module 50 may further include a third resistor R4. One end of the third resistor R4 is connected to the gate of the control transistor Q4, and the other end of the third resistor R4 is connected to the interrupt control terminal Pulse, so that the gate of the control transistor Q4 is connected to the interrupt control terminal Pulse through the third resistor R4, and the control transistor Q4 is prevented from being damaged due to excessive current flowing through the control transistor Q4.

In this way, the control transistor Q4 is controlled to be turned on by the interrupt control signal, and then the switching transistor Q5 is controlled to be connected to the ground GND by controlling the control transistor Q4 to be turned on, so that the switching transistor Q5 is controlled to be turned off rapidly.

Referring to fig. 2, in some embodiments, the driving circuit 100 further includes a voltage stabilizing module 70 and a load resistor R5. One end of the voltage stabilizing module 70 is connected with the source electrode of the switching transistor Q5, and the other end is connected with the grid electrode of the switching transistor Q5. The voltage stabilizing module 70 is used for limiting the voltage difference between the source and the gate of the switching transistor Q5. One end of the load resistor R5 is connected with the gate of the switching transistor Q5, and the other end is connected with the source of the switching transistor Q5.

Specifically, the voltage stabilizing module 70 includes a first zener diode ZD1 and a second zener diode ZD2, where an anode of the first zener diode ZD1 is connected to a source of the switching transistor Q5, a cathode of the first zener diode ZD1 is connected to a cathode of the second zener diode ZD2, and an anode of the second zener diode ZD2 is connected to a gate of the switching transistor Q5 and one end of the current limiting resistor R3, respectively.

It can be appreciated that, since the positive electrode of the first zener diode ZD1 is connected to the source electrode of the switching transistor Q5, the negative electrode of the first zener diode ZD1 is connected to the negative electrode of the second zener diode ZD2, and the positive electrode of the second zener diode ZD2 is respectively connected to the gate electrode of the switching transistor Q5, the first zener diode ZD1 and the second zener diode ZD2 can limit the voltage difference between the source electrode and the gate electrode of the switching transistor Q5 when the switching transistor Q5 is turned on.

Specifically, one end of the load resistor R5 is connected to the gate of the switching transistor Q5, and the other end of the load resistor R5 is connected to the source of the switching transistor Q5 and the positive electrode B of the power supply VBAT, respectively, and when the switching transistor Q5 is turned on, the load resistor R5 may be used to consume an unwanted amount of power generated in the circuit when the switching transistor Q5 is turned on.

Optionally, the driving circuit 100 may further include a fourth resistor R6. The other end of the voltage stabilizing module 70 may be connected to the gate of the switching transistor Q5 through the fourth resistor R6, and the other end of the voltage stabilizing module 70 is connected to the gate of the switching transistor Q5 through the fourth resistor R6, so as to prevent the switching transistor Q5 from being damaged due to excessive current flowing through the switching transistor Q5.

In this way, the voltage when the switching transistor Q5 is turned on is stabilized by providing the voltage stabilizing module 70 in the driving circuit 100, and the unnecessary power generated in the circuit is consumed during the time when the switching transistor Q5 is turned on by providing the load resistor R5, thereby preventing the circuit from being shorted.

Referring to fig. 1, the present utility model further provides a power management system 1000. The power management system 1000 includes a power supply VBAT, a switching transistor Q5 in series with a positive pole B of the power supply VBAT, and the driving circuit 100 of any of the above embodiments. For brevity, the description is omitted here.

In this way, in the power management system 1000 of the present utility model, the switch driving module 10 is connected to the PWM terminal PWM, the reference voltage terminal U and the node N, and when the voltage of the node N needs to be adjusted, the voltage of the node N is adjusted by the PWM signal of the PWM terminal PWM and the voltage of the reference voltage terminal U, and the voltage doubling circuit 30 is connected to the positive electrode B of the power supply VBAT, the gate of the switching transistor Q5 and the node N, and when the switching transistor Q5 needs to be turned on, the switching transistor Q5 is driven to be turned on according to the output voltage of the power supply VBAT and the voltage of the node N. Thus, the power management system 1000 of the present utility model is composed of diodes and electronic devices such as switching transistors, resistors and capacitors, and low-power transistors, which simplifies the circuit structure, reduces the cost, and facilitates mass production as compared with the current driving circuit 100. And the voltage of the node N is regulated by setting the switch driving module 10, so that the allowable voltage range of the positive end of the power supply VBAT can be increased, and the problem that the switch transistor Q5 is easily damaged due to incomplete starting of the switch transistor Q5 caused by the fact that the voltage is larger than a preset threshold value is avoided.

Referring to fig. 3, in some embodiments, the switching transistor Q5 of the power management system 1000 includes a discharging switching transistor Q51 and a charging switching transistor Q52. The driving circuit 100 includes two driving circuits 100, wherein one driving circuit 100 is connected to the discharging switch transistor Q51 for controlling the on and off of the discharging switch transistor Q51. The other driving circuit 100 is connected to the charge switch transistor Q52 for controlling the charge switch transistor Q52 to be turned on and off. Note that BAT in fig. 3 represents an output of the power supply VBAT.

In this way, by providing two driving circuits 100 in the power management system 1000, one driving circuit 100 is connected to the discharging transistor, and the other driving circuit 100 is connected to the charging switch transistor Q52, the power management system 1000 has a discharging function while having a specific charging function.

Referring to fig. 3, in some embodiments, the power management system 1000 further includes a fuse resistor R7. The fuse resistor R7 is connected to the power supply VBAT.

Specifically, one end of the fuse resistor R7 is connected to the positive electrode B of the power supply VBAT, and the other end of the fuse resistor R7 is connected to the drain of the switching transistor Q5. When the current in the circuit is excessive, the fusing resistor R7 can be fused to disconnect the switching transistor Q5 from the positive electrode B of the power supply VBAT, so as to prevent the excessive current from flowing through the circuit, and damage to electronic components in the circuit.

The number of the fuse resistors R7 may be one or plural, and is not limited herein.

In this way, by providing the fuse resistor R7, when the current output from the positive electrode B of the power supply VBAT is excessive, the positive electrode B of the power supply VBAT is disconnected from the drain of the switching transistor Q5, so that the excessive current flowing through the circuit is prevented from damaging the electronic components in the circuit.

In the description of the present specification, reference to the terms "one embodiment," "certain embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiments or examples. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

While embodiments of the present utility model have been shown and described, it will be understood by those of ordinary skill in the art that: many changes, modifications, substitutions and variations may be made to the embodiments without departing from the spirit and principles of the utility model, the scope of which is defined by the claims and their equivalents.

Claims

1. The utility model provides a drive circuit, its characterized in that is used for power management system, power management system includes power and switching transistor, switching transistor set up in the anodal power supply path of power, drive circuit is used for controlling switching transistor opens and shuts, drive circuit includes:

2. The driving circuit according to claim 1, wherein the switching transistors include a discharge switching transistor and a charge switching transistor, the driving circuit includes two, one of the driving circuits is connected to the discharge switching transistor for controlling on and off of the discharge switching transistor, and the other driving circuit is connected to the charge switching transistor for controlling on and off of the charge switching transistor.

3. The drive circuit of claim 1, wherein the switching transistor comprises an NMOS transistor.

4. The driving circuit according to claim 1, wherein the voltage doubling circuit is configured to generate a second driving voltage according to the voltage of the source and the first driving voltage of the node, and drive the switching transistor to be turned on, where the second driving voltage is positively correlated with the voltage of the source, and the second driving voltage is greater than the first driving voltage and less than or equal to a sum of the first driving voltage and the voltage of the source.

5. The drive circuit of claim 1, wherein the switch drive module comprises:

6. The drive circuit of claim 1, wherein the switch drive module further comprises:

and the positive electrode of the clamping diode is connected with the node, and the negative electrode of the clamping diode is connected with the reference voltage end.

7. The drive circuit of claim 5, wherein the switch drive module further comprises:

8. The drive circuit according to claim 1, wherein the voltage doubler circuit includes:

9. The drive circuit of claim 8, wherein the drive circuit further comprises:

10. The drive circuit of claim 1, wherein the drive circuit further comprises:

11. The drive circuit of claim 10, wherein the shutdown module comprises:

12. The drive circuit of claim 1, wherein the drive circuit further comprises:

13. A power management system comprising a power supply, a switching transistor and the drive circuit of any of claims 1-12, the switching transistor being disposed in a positive supply path of the power supply.

14. The power management system of claim 13, further comprising a fuse resistor, the fuse resistor connected to the power source.