Driving circuit, H-bridge driving circuit, H-bridge circuit and power device

Abstract

The utility model relates to the technical field of electronic circuits, in particular to a driving circuit, an H-bridge driving circuit, an H-bridge circuit and a power device. According to the utility model, the first driving branch and the second driving branch which output signals with opposite phases are arranged at the output end of the push-pull circuit, the input end of the push-pull circuit is used as the control end of the driving circuit, and finally the first driving branch and the second driving branch output driving signals with opposite phases. And the two driving signals with opposite phases are adopted to control a switching power tube in the H bridge. According to the embodiment of the invention, only two driving chips are needed to respectively drive the left half bridge and the right half bridge of the H-bridge circuit, meanwhile, the driving circuit does not contain other digital circuits, and only simple components are adopted, so that the cost is lower, and the output stability is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of electronic circuits, and in particular to a drive circuit, an H-bridge drive circuit, an H-bridge circuit and a power device. Background Art

[0002] H-bridge is an electronic circuit. Because its circuit shape resembles the letter H, it is named "H-bridge". It can reverse the voltage / current of the connected load or output terminal. This type of circuit can be used for forward and reverse control and speed control of DC motors in robots and other practical occasions, stepper motor control (bipolar stepper motors must also include two H-bridge motor controllers), most DC-AC converters (such as inverters and frequency converters) in power conversion, some DC-DC converters (push-pull converters), etc., and other power electronic devices.

[0003] Most of the H-bridge driving circuits currently used use a driver chip to control 4 PWM signals as control signals to drive the H-bridge. This driving method is relatively expensive. Of course, there are also "H-bridge driving circuit and electrical system based on H-bridge driving circuit" disclosed in the publication number "CN211930519U", which uses 2 driver chips to drive the left and right bridge arms of the H-bridge respectively, and outputs 4 PWM signals to control the H-bridge to achieve driving. Although it uses 2 driver chips, there is a more complex digital signal processor inside the chip, which has more stringent requirements on the fluctuation range of voltage and current, and is easily interfered, resulting in unstable driving circuit and damage to the device.

[0004] Therefore, a driving circuit of an H-bridge with lower cost, simpler circuit and better stability is needed. Utility Model Content

[0005] In view of the deficiencies in the prior art, the utility model provides a driving circuit which adopts 2-way PWM driving signals to realize a driving circuit for driving an H-bridge, and has the characteristics of simpler circuit and better stability.

[0006] The utility model discloses a driving circuit through an embodiment, comprising: a push-pull circuit, a first driving branch and a second driving branch; wherein the input end of the push-pull circuit is connected to an external driving device, the output end of the push-pull circuit is connected to the input end of the first driving branch and the input end of the second driving branch, the output signals of the first driving branch and the second driving branch are in phase opposition, and the first driving branch and the second driving branch are both used to drive a switch power tube. The driving circuit also includes a power supply for providing the power required by the push-pull circuit, the first driving branch and the second driving branch.

[0007] Furthermore, the power supply includes a first power supply and a second power supply, wherein the first power supply is used to provide power for the push-pull circuit, and the second power supply is used to provide power for the first driving branch or the second driving branch.

[0008] Furthermore, the push-pull circuit includes a first transistor and a second transistor; the base of the first transistor is connected to the base of the second transistor, and is connected to an external driving device as an input end of the push-pull circuit; the collector of the first transistor is connected to a first power supply; the collector of the second transistor is grounded; the emitter of the first transistor is connected to the emitter of the second transistor, and is connected as an output end of the push-pull circuit.

[0009] Furthermore, a first resistor is connected in series between the input end of the push-pull circuit and the external driving device. The first resistor is used to limit the current so that the current flowing into the first transistor and the second transistor is stable.

[0010] Furthermore, the first driving branch includes a second resistor and a transistor inverter circuit, one end of the second resistor is connected to the output end of the push-pull circuit as the input end of the first driving branch, and the other end is connected to the input end of the transistor inverter circuit; the output end of the transistor inverter circuit serves as the output end of the first driving branch.

[0011] Furthermore, the second driving branch includes a third resistor and a fifth resistor; one end of the third resistor is connected to the output end of the push-pull circuit as the input end of the second driving branch, and the other end transmits or outputs the driving signal; one end of the fifth resistor is connected to one end of the third resistor that transmits or outputs the driving signal, and the other end is grounded.

[0012] Preferably, the second driving branch further comprises a first diode, wherein the anode of the first diode is connected to one end of the third resistor for transmitting or outputting the driving signal, and the cathode of the first diode is connected to the end for transmitting or outputting the driving signal.

[0013] To achieve the above objectives, the utility model also discloses an H-bridge driving circuit, which includes a left bridge driving circuit and a right bridge driving circuit, which are respectively used to drive the left bridge and the right bridge of the H-bridge, and the left bridge driving circuit and the right bridge driving circuit are the above-mentioned driving circuits.

[0014] To achieve the above purpose, the utility model also discloses an H-bridge circuit, which includes the above H-bridge driving circuit and an H-bridge, wherein the H-bridge includes a left bridge circuit and a right bridge circuit. The output end of the left bridge driving circuit is connected to the driving input end of the left bridge circuit to drive the left bridge of the H-bridge; the output end of the right bridge driving circuit is connected to the driving input end of the right bridge circuit to drive the right bridge of the H-bridge.

[0015] To achieve the above object, the utility model also discloses a power device, which includes the above H-bridge drive circuit or the above H-bridge circuit.

[0016] Compared with the prior art, the utility model has the following beneficial effects: by adopting two PWM control signals, the purpose of controlling the H-bridge can be achieved, the cost is lower, but a warmer driving signal can be output. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solution of the utility model and facilitate further understanding of the technical effects, technical features and purposes of the utility model, the utility model is described in detail below in conjunction with the accompanying drawings. The accompanying drawings constitute an essential part of the specification and are used together with the embodiments of the utility model to illustrate the technical solution of the utility model, but do not constitute a limitation to the utility model.

[0018] Figure 1 A schematic diagram of a driving circuit described in the present utility model;

[0019] Figure 2 This is a schematic diagram of the H-bridge driving circuit described in the utility model;

[0020] Figure 3 It is a schematic diagram of the H-bridge circuit recorded in the utility model;

[0021] Figure 4 When the utility model is implemented with an H-bridge circuit schematic diagram, the current flow diagram is Figure 1 ;

[0022] Figure 5 When the utility model is implemented with an H-bridge circuit schematic diagram, the current flow diagram is Figure 2 ;

[0023] Figure 6 It is a schematic diagram of the structure of the power device in the utility model.

[0024] Among them, 1-push-pull circuit, 2-first drive branch, 3-second drive branch, 4-left bridge drive circuit, 5-right bridge drive circuit, 6-power device, PWM1-first drive signal output by the external drive device, PWM2-second drive signal output by the external drive device, Q1-first transistor, Q2-second transistor, Q3-third transistor, Q4-fourth NMOS transistor, Q5-fifth NMOS transistor, Q6-sixth NMOS transistor, Q7-seventh NMOS transistor, Q8-eighth NPN transistor, Q9-ninth transistor, Q10-tenth transistor, R1-first resistor, R2-second resistor, R3-third resistor, R4-third resistor, R5-fourth resistor, R6-sixth resistor, R7-seventh resistor, R8-eighth resistor, R9-ninth resistor, R10-tenth resistor, D1-first diode, D2-second diode. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. Of course, the specific embodiments described below are only for explaining the technical solution of the present invention, rather than for limiting the present invention. In addition, the parts described in the embodiments or drawings are only examples of the relevant parts of the present invention, rather than the entirety of the present invention. At the same time, based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field should naturally belong to the protection scope of the present invention.

[0026] Embodiment 1

[0027] like Figure 1 A driving circuit shown in the figure includes: a push-pull circuit 1, a first driving branch 2 and a second driving branch 3; wherein the input end of the push-pull circuit 1 is connected to an external driving device, and the external driving device outputs a first driving signal PWM1, and the output end of the push-pull circuit 1 is connected to the input end of the first driving branch 2 and the input end of the second driving branch 3, the output signals of the first driving branch 2 and the second driving branch 3 are in anti-phase, and the first driving branch 2 and the second driving branch 3 are both used to drive the switching power tube. The driving circuit also includes a power supply, wherein the power supply includes a first power supply of 12V and a second power supply of 30V, wherein the first power supply is used to provide power for the push-pull circuit, and the second power supply is used to provide power for the first driving branch or the second driving branch. Figure 3 As shown, when the driving circuit is used, the first driving branch of the driving circuit is used to drive the upper bridge of the H bridge, and the second driving branch of the driving circuit is used to drive the lower bridge of the H bridge.

[0028] In this embodiment, the push-pull circuit 1 includes a first transistor Q1 and a second transistor Q2; the base of the first transistor Q1 and the base of the second transistor Q2 are connected, and are connected to an external driving device as the input end of the push-pull circuit 1; the collector of the first transistor Q1 is connected to a 12V first power supply; the collector of the second transistor Q2 is grounded; the emitter of the first transistor Q1 and the emitter of the second transistor Q2 are connected, and are used as the output end of the push-pull circuit 1. Among them, the first transistor Q1 is an NPN transistor, and the second transistor Q2 is a PNP transistor. The two transistors with the same parameters in the push-pull circuit are alternately turned on, so that the output power can reach twice that of a single transistor, thereby improving the power output, providing a greater current driving capability, while reducing the conduction loss and improving the efficiency.

[0029] In this embodiment, a first resistor R1 is connected in series between the input end of the push-pull circuit 1 and the external driving device. The first resistor R1 is used to limit the current so that the current flowing into the first transistor Q1 and the second transistor Q2 is stable.

[0030] In this embodiment, the first driving branch 1 includes a second resistor R2 and a transistor inverting circuit, wherein the transistor inverting circuit is composed of an NPN transistor. Among them, one end of the second resistor R2 is connected to the output end of the push-pull circuit 1 as the input end of the first driving branch 2, and the other end is connected to the base of the third transistor Q3; the emitter of the third transistor Q3 is grounded, and the collector of the third transistor Q3 is connected to one end of the fourth resistor R4; the other end of the fourth resistor R4 is connected to the second power supply of 30V, and the collector of the third transistor Q3 is used as the output end of the first driving branch 1. Of course, in some other embodiments, a transistor inverting circuit composed of a PNP transistor can also be used.

[0031] In this embodiment, the second driving branch 3 includes a third resistor R4, a first diode D1 and a fifth resistor R5. Among them, one end of the third resistor R3 is connected to the output end of the push-pull circuit 1 as the input end of the second driving branch 3, and the other end is connected to the positive electrode of the first diode D1. The negative electrode of the first diode D1 serves as the output end of the second driving branch 3. At the same time, the fifth resistor R5 is connected to the negative electrode of the first diode D1 and then grounded.

[0032] This embodiment can drive the upper bridge and the lower bridge on one side of the H-bridge circuit with one driving signal. Meanwhile, the circuit is composed of only simple components, which has the advantages of saving cost and driving chips.

[0033] Embodiment 2

[0034] like Figure 2 An H-bridge driving circuit is shown, which includes a left bridge driving circuit 4 and a right bridge driving circuit 5, wherein the left bridge driving circuit 4 and the right bridge driving circuit 5 are both the above-mentioned driving circuits, and when used, are used to drive the left bridge and the right bridge of the H-bridge respectively. This embodiment uses two identical driving circuits to form the driving circuit of the H-bridge, which has the characteristic of lower cost.

[0035] Embodiment 3

[0036] like Figure 3 An H-bridge circuit shown includes the above-mentioned H-bridge driving circuit and an H-bridge. The first driving branch of the driving circuit is used to drive the upper bridge of the H-bridge, and the second driving branch of the driving circuit is used to drive the lower bridge of the H-bridge. The four switching power tubes of the H-bridge are four NMOS tubes, namely the fourth NMOS tube Q4, the fifth NMOS tube Q5, the sixth NMOS tube Q6 and the seventh NMOS tube Q7. The drain of the fourth NMOS tube Q4 and the fourth resistor R4 in the driving circuit share a 30V second power supply, and the drain of the sixth NMOS tube Q6 and the sixth resistor R6 share a 30V second power supply; the source of the fifth NMOS tube Q5 and the seventh NMOS tube Q7 are grounded.

[0037] Working principle:

[0038] The circuit is described below by taking the third embodiment as an example.

[0039] In the third embodiment, the first transistor Q1 is an NPN transistor, the second transistor Q2 is a PNP transistor, the ninth transistor Q9 is an NPN transistor, and the tenth transistor Q10 is a PNP transistor.

[0040] like Figure 4 As shown, taking the first driving signal PWM1 output by the external driving device as a high-level signal and the second driving signal PWM2 as a low-level signal as an example. At this time, for the first driving circuit on the left, the first transistor Q1 is turned on, the second transistor Q2 is turned off, the third transistor Q3 is turned on, the fourth NMOS transistor Q4 is turned off, and the fifth NMOS transistor Q5 is turned on, and the current flows of the left half bridge are as follows: the first driving signal PWM1 flows through the first resistor R1, the first transistor Q1, the third resistor R3, the first diode D1, the fifth NMOS transistor Q5 and then to the ground; the current of the 12V first power supply flows through the first transistor Q1, the third resistor R3, the first diode D1, the fifth NMOS transistor Q5 and then to the ground; the current of the 30V second power supply flows through the fourth resistor R4 and the third transistor Q3 and then to the ground. For the second drive circuit on the right, the sixth NMOS tube Q6 is turned on, the seventh NMOS tube Q7 is turned off, the eighth NPN transistor Q8 is turned off, the ninth transistor Q9 is turned off, and the tenth transistor Q10 is turned on. The current flows of the right half bridge are as follows: the second drive signal PWM2 flows through the tenth resistor R10 and the tenth transistor Q10 and then reaches the ground, the 12V first power supply has no current output, and the 30V second power supply flows to the load after passing through the sixth NMOS tube Q6.

[0041] In summary, the current of the second power supply is input from the right end of the load, output from the left end, and reaches the ground through the fifth NMOS transistor Q5, thereby completing the driving of the load.

[0042] like Figure 5As shown, take the example that the external driving device outputs the first driving signal PWM1 as a low-level signal and the second driving signal PWM2 as a high-level signal. At this time, for the first driving circuit on the left, the first transistor Q1 is turned off, the second transistor Q2 is turned on, the third transistor Q3 is turned off, the fourth NMOS transistor Q4 is turned on, and the fifth NMOS transistor Q5 is turned off. The current flows of the left half bridge are as follows: the first driving signal PWM1 flows through the first resistor R1 and the second transistor Q2 and then reaches the ground; the first power supply of 12V has no current output; the second power supply of 30V flows to the load after passing through the fourth NMOS transistor Q4. For the second drive circuit on the right, the sixth NMOS tube Q6 is turned off, the seventh NMOS tube Q7 is turned on, the eighth NPN transistor Q8 is turned on, the ninth transistor Q9 is turned on, and the tenth transistor Q10 is turned off. The current flows of the right half bridge are as follows: the second drive signal PWM2 flows through the tenth resistor R10, the ninth transistor Q9, the ninth resistor R9, the second diode D2, the seventh NMOS tube Q7 and then to the ground; the current of the 12V first power supply flows through the ninth transistor Q9, the ninth resistor R9, the second diode D2, the seventh NMOS tube Q7 and then to the ground; the current of the 30V second power supply flows through the sixth resistor R6 and the eighth NPN transistor Q8 and then to the ground.

[0043] In summary, the current of the second power supply is input from the left end of the load, output from the right end, and reaches the ground through the seventh NMOS transistor Q7, thereby completing the driving of the load.

[0044] In this embodiment, a push-pull circuit is combined with an N-type MOS tube, and only two PWM input signals are needed to drive the H-bridge circuit, thereby reducing the cost of the driver chip. At the same time, the driver circuit does not contain other digital circuits and is composed of only simple components, so its output is more stable and more consistent.

[0045] Embodiment 4

[0046] like Figure 6 As shown, a power device is integrated with the H-bridge circuit described in Example 3, wherein the IN1 and IN2 pins are the drive signal input terminals of the power device, and the OUT1 and OUT2 pins are the output terminals of the power device. The power supply input pin and the ground pin of the power device are not marked in the figure. The drive signal output by the power device has better stability and higher consistency.

[0047] It should be noted that the above embodiments are only for more clearly illustrating the technical solution of the present invention. Those skilled in the art will understand that the implementation methods of the present invention are not limited to the above contents, and obvious changes, replacements or substitutions based on the above contents do not exceed the scope covered by the technical solution of the present invention; other implementation methods will naturally fall within the scope of the present invention without departing from the concept of the present invention.

Claims

1. A driving circuit, characterized in that: include: A push-pull circuit, a first driving branch and a second driving branch; The input end of the push-pull circuit is connected to an external driving device, the output end of the push-pull circuit is connected to the input end of the first driving branch and the input end of the second driving branch, the output signals of the first driving branch and the second driving branch are in anti-phase, and the outputs of the first driving branch and the second driving branch are used to connect and drive the switch power tube; It also includes a power supply for providing the push-pull circuit, the first driving branch and the second driving branch with the required power.

2. The driving circuit according to claim 1, wherein: The power supply includes a first power supply and a second power supply, wherein the first power supply is used to provide power for the push-pull circuit, and the second power supply is used to provide power for the first driving branch or the second driving branch.

3. The driving circuit according to claim 1, wherein: The push-pull circuit includes a first transistor and a second transistor; the base of the first transistor is connected to the base of the second transistor, and is connected to an external driving device as an input end of the push-pull circuit; the collector of the first transistor is connected to a first power supply; the collector of the second transistor is grounded; the emitter of the first transistor is connected to the emitter of the second transistor, and is connected to the output end of the push-pull circuit.

4. The driving circuit according to claim 1, wherein: The input end of the push-pull circuit is also connected to a first resistor, and the external driving device transmits a driving signal to the push-pull circuit through the first resistor.

5. The driving circuit according to claim 2, wherein: The first driving branch includes a second resistor and a transistor inverter circuit, one end of the second resistor is connected to the output end of the push-pull circuit as the input end of the first driving branch, and the other end is connected to the input end of the transistor inverter circuit; the output end of the transistor inverter circuit serves as the output end of the first driving branch.

6. The driving circuit according to claim 1, wherein: The second driving branch includes a third resistor and a fifth resistor; one end of the third resistor is connected to the output end of the push-pull circuit as the input end of the second driving branch, and the other end transmits or outputs a driving signal; one end of the fifth resistor is connected to one end of the third resistor that transmits or outputs a driving signal, and the other end is grounded.

7. The driving circuit according to claim 6, wherein: The second driving branch further includes a first diode, the anode of the first diode is connected to one end of the third resistor for transmitting or outputting a driving signal, and the cathode of the first diode is used for transmitting or outputting a driving signal.

8. An H-bridge driving circuit, characterized in that: It comprises a left bridge driving circuit and a right bridge driving circuit, which are used to drive the left bridge and the right bridge of the H bridge respectively, and the left bridge driving circuit and the right bridge driving circuit are the driving circuits as described in any one of claims 1-7.

9. An H-bridge circuit, characterized in that: The H-bridge driving circuit according to claim 8 further comprises an H-bridge, wherein the H-bridge comprises a left bridge circuit and a right bridge circuit; The output end of the left bridge driving circuit is connected to the driving input end of the left bridge circuit, and the output end of the right bridge driving circuit is connected to the driving input end of the right bridge circuit.

10. A power device, characterized in that: It comprises the H-bridge driving circuit as claimed in claim 8 or the H-bridge circuit as claimed in claim 9.

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