阅读说明：本技术 一种电机驱动电路及其开关管驱动电路 (Motor drive circuit and switching tube drive circuit thereof ) 是由 王永秋 孙盼龙 吴青艳 于 2018-07-05 设计创作，主要内容包括：本发明提供一种电机驱动电路及其开关管驱动电路,开关管驱动电路包括比较器和状态检测模块,各比较器的反相输入端连接状态检测模块,正相输入端连接控制器上的控制信号输出接口,输出端连接H桥电机驱动电路中开关管的控制极；状态检测模块用于检测控制器是否处于上电和/或复位状态；当控制器处于上电和/或复位状态时,状态检测模块向比较器的反相输入端发送高电位信号,否则向比较器的反相输入端发送低电位信号。本发明所提供的技术方案,当控制器上电或复位时,被驱动的开关管接收不到控制器所发出的控制信号,H桥驱动电路中不会出现同侧开关管同时导通的现象,所以能够提高H桥驱动电路的安全性。(The invention provides a motor driving circuit and a switching tube driving circuit thereof, wherein the switching tube driving circuit comprises comparators and a state detection module, the inverting input end of each comparator is connected with the state detection module, the non-inverting input end of each comparator is connected with a control signal output interface on a controller, and the output end of each comparator is connected with a control electrode of a switching tube in an H-bridge motor driving circuit; the state detection module is used for detecting whether the controller is in a power-on state and/or a reset state; when the controller is in a power-on and/or reset state, the state detection module sends a high-potential signal to the inverting input end of the comparator, otherwise, the state detection module sends a low-potential signal to the inverting input end of the comparator. According to the technical scheme provided by the invention, when the controller is powered on or reset, the driven switch tube cannot receive the control signal sent by the controller, and the phenomenon that the switch tubes on the same side are simultaneously conducted in the H-bridge driving circuit cannot occur, so that the safety of the H-bridge driving circuit can be improved.)

1. A motor driving circuit comprises a controller and an H-bridge motor driving circuit which is composed of a first switching tube, a second switching tube, a third switching tube and a fourth switching tube, wherein control poles of the switching tubes are respectively provided with corresponding switching tube driving circuits;

the H-bridge motor driving circuit is characterized in that in the switching tubes on the same side of the H-bridge motor driving circuit, the driving circuit of at least one switching tube is an anti-misoperation switching tube driving circuit;

each misoperation prevention switch tube driving circuit comprises a corresponding comparator and a state detection module, wherein the reverse phase input end of each comparator is connected with the corresponding state detection module, the normal phase input end of each comparator is connected with the corresponding control signal output interface on the controller, and the output end of each comparator is connected with the control electrode of the corresponding switch tube in the H-bridge motor driving circuit;

the state detection module is used for detecting whether the controller is in a power-on and/or reset state; when the controller is in a power-on and/or reset state, the state detection module sends a high-potential signal to the inverting input end of the corresponding comparator, otherwise, the state detection module sends a low-potential signal to the inverting input end of the corresponding comparator.

2. A motor driving circuit according to claim 1, wherein each of the state detecting modules includes a corresponding fifth switching tube; the anode of each fifth switching tube is connected with the inverted input end of the corresponding comparator, the cathode and the control electrode are grounded, and corresponding pull-down resistors are respectively arranged on the lines of the control electrodes of the switching tubes, which are grounded; and the control electrode of each fifth switching tube is also connected with the corresponding enable output end on the controller, and each enable output port of the controller outputs a high-level signal when the controller is powered on.

3. A motor drive circuit as claimed in claim 2, wherein the line on which the inverting output of each comparator is connected to the power supply is provided with a respective first pull-up resistor.

4. A motor drive circuit as claimed in claim 2 or 3, wherein the output of each comparator is also for connection to a power supply, and a respective second pull-up resistor is provided on a respective line at the output of each comparator for connection to the power supply.

5. A motor drive circuit as claimed in claim 2, wherein each of the fifth switching transistors is a triode.

6. The motor driving circuit according to claim 1, wherein the first switching tube, the second switching tube, the third switching tube and the fourth switching tube are MOS tubes.

7. A switching tube driving circuit is characterized by comprising a controller, a comparator and a state detection module; the inverting input end of the comparator is connected with the state detection module, the non-inverting input end of the comparator is connected with the control signal output interface of the controller, and the output end of the comparator is used for being connected with the control electrode of the driven switching tube;

the state detection module is used for detecting whether the controller is in a power-on and/or reset state, and when the controller is in the power-on and/or reset state, the state detection module sends a high-potential signal to the inverting input end of the comparator, otherwise, the state detection module sends a low-potential signal to the inverting input end of the comparator.

8. The switch tube driving circuit according to claim 7, wherein the state detection module comprises a switch tube; the anode of the switching tube is connected with the inverting input end of the comparator, the cathode and the control electrode are used for grounding, and pull-down resistors are respectively arranged on the lines of the control electrode of the switching tube, which are used for grounding; and the control electrode of the switching tube is also connected with an enable output end on the controller, and when the controller is electrified, the enable output end of the controller outputs a high-level signal.

9. The switch tube driving circuit according to claim 7, wherein a first pull-up resistor is disposed on a line for connecting the inverting input terminal of the comparator to a power supply.

10. The switch tube driving circuit according to claim 7, wherein the output terminal of the comparator is further configured to be connected to a power supply, and a second pull-up resistor is disposed on a corresponding line of the output terminal of the comparator configured to be connected to the power supply.

Technical Field

The invention belongs to the technical field of power electronics, and particularly relates to a motor driving circuit and a switching tube driving circuit thereof.

Background

The H-bridge driving circuit is a very typical motor driving circuit, and the structure of the H-bridge driving circuit is shown in fig. 1, and the H-bridge driving circuit comprises four switching tubes of T1, T2, T3 and T4, and the motor driving circuit is implemented by controlling the on and off of each switching tube. The motor drive circuit is called an H-bridge drive circuit because it is shaped like the letter H.

When the H-bridge driving circuit works, one of the switching tubes is conducted to the positive electrode to realize the pull-up of the electric potential of the motor, the other MOS tube is conducted to the negative electrode to realize the pull-down of the electric potential of the motor, and the driving of the motor is realized through switching.

Each switch tube in the H-bridge drive circuit is generally driven and controlled by a drive signal generated by a controller such as a singlechip and the like, but when the controller is powered on or reset, a pin of the controller is generally in an input state, if the controller is interfered by the outside at the moment, the switch tubes on the same side in the H-bridge drive circuit are conducted, and the motor works abnormally; if the switch tubes on the same side in the H-bridge driving circuit are conducted, a short circuit between the positive electrode and the negative electrode of a power supply can be caused, the switch tubes arranged on the bridge arm are burnt, and the problem of poor safety of the H-bridge driving circuit is caused.

Disclosure of Invention

The invention aims to provide a motor driving circuit and a switching tube driving circuit thereof, which are used for solving the problem that when a controller in the conventional switching tube control circuit is powered on or reset, the switching tube on the same side in an H-bridge driving circuit is conducted due to the fact that a tube pin of the controller is in an input state, and further the safety of the H-bridge driving circuit is poor.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a motor driving circuit comprises a controller and an H-bridge motor driving circuit which is composed of a first switching tube, a second switching tube, a third switching tube and a fourth switching tube, wherein control poles of the switching tubes are respectively provided with corresponding switching tube driving circuits;

in the switching tubes on the same side of the H-bridge motor driving circuit, the driving circuit of at least one switching tube is an anti-misoperation switching tube driving circuit;

each misoperation prevention switch tube driving circuit comprises a corresponding comparator and a state detection module, wherein the reverse phase input end of each comparator is connected with the corresponding state detection module, the normal phase input end of each comparator is connected with the corresponding control signal output interface on the controller, and the output end of each comparator is connected with the control electrode of the corresponding switch tube in the H-bridge motor driving circuit;

the state detection module is used for detecting whether the controller is in a power-on and/or reset state; when the controller is in a power-on and/or reset state, the state detection module sends a high-potential signal to the inverting input end of the corresponding comparator, otherwise, the state detection module sends a low-potential signal to the inverting input end of the corresponding comparator.

According to the technical scheme provided by the invention, the comparator is arranged in the misoperation prevention switch tube driving circuit, and under the action of the comparator, when the controller is powered on or reset, the driven switch tube cannot receive the control signal sent by the controller, and the phenomenon that the switch tubes on the same side are simultaneously conducted in the H-bridge driving circuit cannot occur, so that the safety of the H-bridge driving circuit can be improved.

As a further improvement to the state detection modules, each state detection module includes a corresponding fifth switching tube; the anode of each fifth switching tube is connected with the inverted input end of the corresponding comparator, the cathode and the control electrode are grounded, and corresponding pull-down resistors are respectively arranged on the lines of the control electrodes of the switching tubes, which are grounded; and the control electrode of each fifth switching tube is also connected with the corresponding enable output end on the controller, and each enable output port of the controller outputs a high-level signal when the controller is powered on.

As a further improvement on the inverting input end of each comparator, a corresponding first pull-up resistor is arranged on a circuit for connecting the inverting output end of each comparator with a power supply.

As a further improvement of the output end of each comparator, the output end of each comparator is also used for connecting a power supply, and corresponding second pull-up resistors are respectively arranged on corresponding lines of the output ends of each comparator, which are used for connecting the power supply.

As a further improvement to the fifth switching tubes, each fifth switching tube is a triode.

As a further improvement on each switching tube in the H-bridge motor driving circuit, the first switching tube, the second switching tube, the third switching tube and the fourth switching tube are all MOS tubes.

A switching tube driving circuit comprises a controller, a comparator and a state detection module; the inverting input end of the comparator is connected with the state detection module, the non-inverting input end of the comparator is connected with the control signal output interface of the controller, and the output end of the comparator is used for being connected with the control electrode of the driven switching tube;

the state detection module is used for detecting whether the controller is in a power-on and/or reset state, and when the controller is in the power-on and/or reset state, the state detection module sends a high-potential signal to the inverting input end of the comparator, otherwise, the state detection module sends a low-potential signal to the inverting input end of the comparator.

As a further improvement to the state detection module, the state detection module comprises a switch tube; the anode of the switching tube is connected with the inverting input end of the comparator, the cathode and the control electrode are used for grounding, and pull-down resistors are respectively arranged on the lines of the control electrode of the switching tube, which are used for grounding; and the control electrode of the switching tube is also connected with an enable output end on the controller, and when the controller is electrified, the enable output end of the controller outputs a high-level signal.

As a further improvement of the comparator, a first pull-up resistor is arranged on a line of the inverting input end of the comparator, which is used for being connected with a power supply.

As a further improvement of the comparator, the output end of the comparator is also used for connecting a power supply, and a second pull-up resistor is arranged on a corresponding line of the output end of the comparator used for connecting the power supply.

Drawings

FIG. 1 is a schematic diagram of an H-bridge driving circuit in the prior art;

FIG. 2 is a schematic diagram of an H-bridge driving circuit in an embodiment of a motor driving circuit;

fig. 3 is a driving circuit diagram of the first MOS transistor Q1 in the H-bridge driving circuit in the embodiment of the motor driving circuit.

Detailed Description

The invention aims to provide a motor driving circuit and a switching tube driving circuit thereof, which are used for solving the problem that when a controller in the conventional switching tube control circuit is powered on or reset, the switching tube on the same side in an H-bridge driving circuit is conducted due to the fact that a tube pin of the controller is in an input state, and further the safety of the H-bridge driving circuit is poor.

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a motor driving circuit comprises a controller and an H-bridge motor driving circuit which is composed of a first switching tube, a second switching tube, a third switching tube and a fourth switching tube, wherein control poles of the switching tubes are respectively provided with corresponding switching tube driving circuits;

in the switching tubes on the same side of the H-bridge motor driving circuit, the driving circuit of at least one switching tube is an anti-misoperation switching tube driving circuit;

each misoperation prevention switch tube driving circuit comprises a corresponding comparator and a state detection module, wherein the reverse phase input end of each comparator is connected with the corresponding state detection module, the normal phase input end of each comparator is connected with the corresponding control signal output interface on the controller, and the output end of each comparator is connected with the control electrode of the corresponding switch tube in the H-bridge motor driving circuit;

the state detection module is used for detecting whether the controller is in a power-on and/or reset state; when the controller is in a power-on and/or reset state, the state detection module sends a high-potential signal to the inverting input end of the corresponding comparator, otherwise, the state detection module sends a low-potential signal to the inverting input end of the corresponding comparator.

The technical solution of the present invention will be further explained with reference to the specific embodiments.

Motor drive circuit embodiment:

the embodiment provides a motor driving circuit, which adopts an H-bridge driving circuit composed of MOS tubes to drive a motor, and when a controller is powered on or reset, the phenomenon that the MOS tubes on the same side are simultaneously conducted due to the influence of interference signals can be avoided.

The motor driving circuit provided by this embodiment has a structure as shown in fig. 2, and includes a controller U1, and an H-bridge driving circuit composed of a first MOS transistor Q1, a second MOS transistor Q2, a third MOS transistor Q3, and a fourth MOS transistor Q4, and the H-bridge driving circuit is connected to the motor M1 and is configured to drive the motor M1.

Each MOS transistor is correspondingly provided with a MOS transistor driving circuit, the driving circuit of at least one of the switching transistors on the same side of the H-bridge motor driving circuit is an anti-malfunction switching transistor driving circuit, for example, in fig. 2, the first MOS transistor Q1 and the third MOS transistor Q3 are on the same side, and the second MOS transistor Q2 and the fourth MOS transistor Q4 are on the same side, so that the driving circuit of at least one of the first MOS transistor Q1 and the third MOS transistor Q3 is an anti-malfunction switching transistor driving circuit, and the driving circuit of at least one of the second MOS transistor Q2 and the fourth MOS transistor Q4 is an anti-malfunction switching transistor driving circuit. In this embodiment, a driving circuit of the first MOS transistor Q1 is used as a false operation prevention switching transistor driving circuit.

The driving circuit of the first MOS transistor Q1 is shown in fig. 3, and includes a transistor Q5 and a comparator U2, a first enable terminal of the controller U1 is connected to a base of a transistor Q5 through a resistor R1, and a base of a transistor Q5 is further grounded through a pull-down resistor R2; an emitter of the transistor Q5 is grounded, a collector thereof is connected to the power supply Vbat, and a resistor R3 and a resistor R4 are connected in series to a line connecting the collector of the transistor Q5 to the power supply Vbat. The positive phase input end of the comparator U2 is connected with the first control signal output end of the controller, the negative phase input end is connected with the connection point of the resistor R3 and the resistor R4, the output end is connected with the control electrode of the first MOS tube Q1, and in order to ensure the driving effect on the first MOS tube Q1, the output end of the comparator U2 is also connected with a power supply Vbat through a pull-up resistor R5.

The first enable terminal of the controller U1 refers to a port on the controller U1 for sending an enable signal for driving the first MOS transistor Q1, and the port is pulled low by the resistor R1 and the resistor R2 when the controller U1 is powered on and/or reset, and is set low, and outputs a high-level signal when the controller U1 is powered on and/or reset.

The first control signal output terminal of the controller U1 is a port of the controller U1 for sending out a control signal for driving the first MOS transistor Q1, and in this embodiment, the first control signal output terminal of the controller U1 outputs a PWM wave signal.

In this embodiment, the method for driving the first MOS transistor Q1 by the controller U1 includes:

when the controller U1 is in a power-on and/or reset state, under the action of the resistor R1 and the resistor R2, the potential of the first enable end of the controller U1 is pulled low, at this time, the potential of the base of the triode Q5 is low, the triode Q5 is in an off state, the inverting input end of the comparator U2 is high, even if the non-inverting input end of the comparator U2 is high, the signal output by the output end of the comparator U2 is also a low-level signal, the first MOS transistor Q1 cannot be triggered to be switched on, and the phenomenon that MOS transistors on the same side are simultaneously switched on in an H-bridge driving circuit when the controller U1 is powered on and/or reset is avoided;

when the controller U1 is in a normal operating state after power-on and/or reset is completed, the first enable terminal outputs a high-potential signal, the base of the transistor Q5 is at a high potential, the transistor Q5 is triggered to be turned on, the potential of the inverting input terminal of the comparator U2 is pulled low, the signal output by the output terminal of the comparator U2 is the same as the control signal output by the first control signal output terminal of the controller U1, and the first MOS transistor Q1 operates according to the control signal output by the first control signal output terminal of the controller U1 under the action of the pull-up resistor R5.

In this embodiment, the switching tube in the H-bridge driving circuit is an MOS tube; in other embodiments, the switching tube in the H-bridge driving circuit may adopt other fully-controlled switching devices such as a triode, a field effect transistor, and the like.

In this embodiment, the transistor Q5 is used as the fifth switching tube, and as another embodiment, the fifth switching tube may use other fully-controlled switching devices such as MOS tube and field effect tube.

Switching tube drive circuit embodiment:

this embodiment provides a switching transistor driving circuit, which is the same as the MOS transistor driving circuit of the H-bridge driving circuit in the motor driving circuit embodiment, and the driving circuit has been described in detail in the motor driving circuit embodiment, and will not be described here.