阅读说明：本技术 一种马达驱动电路及音圈马达 (Motor driving circuit and voice coil motor ) 是由 鲍永康 于 2021-09-08 设计创作，主要内容包括：本发明实施例提供的一种马达驱动电路及音圈马达,其中所述马达驱动电路中：第一开关单元、第二开关单元、第三开关单元、第四开关单元和马达组成H桥式电路；通过第一延时单元和第二延时单元分别对两输入的控制信号延时,然后第一控制单元和第二控制单元分别对第一开关单元和第二开关单元进行反相控制,实现对第一开关单元和第三开关单元同时打开或关闭,与此同时,实现对第二开关单元和第四开关单元同时关闭或打开,从而可从两个方向驱动马达。本发明的马达驱动电路采用分立器件设计实现,可替代驱动芯片对音圈马达进行驱动,可有效的降低成本。(The embodiment of the invention provides a motor driving circuit and a voice coil motor, wherein the motor driving circuit comprises: the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the motor form an H-bridge circuit; the first delay unit and the second delay unit respectively delay two input control signals, then the first control unit and the second control unit respectively carry out reverse phase control on the first switch unit and the second switch unit, the first switch unit and the third switch unit are opened or closed simultaneously, meanwhile, the second switch unit and the fourth switch unit are closed or opened simultaneously, and therefore the motor can be driven from two directions. The motor driving circuit is realized by adopting a discrete device design, can replace a driving chip to drive the voice coil motor, and can effectively reduce the cost.)

1. A motor drive circuit, comprising: the first switch unit, the second switch unit, the third switch unit, the fourth switch unit, the first control unit, the second control unit, the first delay unit and the second delay unit;

the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the motor form an H-bridge circuit; the input end of the first control unit is connected with the control end of the first switch unit; the input end of the second control unit is connected with the control end of the second switch unit; the first end of the first delay unit is configured to be connected with a first control signal, and the second end of the first delay unit is connected with the control ends of the first control unit and the fourth switch unit; the first end of the second delay unit is configured to be connected with a second control signal, and the second end of the second delay unit is connected with the control ends of the second control unit and the third switch unit; the first control signal and the second control signal are opposite control signals.

2. The motor driving circuit according to claim 1, wherein a first terminal of the first switching unit is connected to an input voltage, and a second terminal of the first switching unit is connected to a first terminal of a third switching unit; the first end of the second switch unit is connected with an input voltage, and the second end of the second switch unit is connected with the first end of the fourth switch unit; the first end of the motor is connected between the first switching unit and the third switching unit, and the second end of the motor is connected between the second switching unit and the fourth switching unit.

3. The motor drive circuit according to claim 1, wherein the first switching unit includes: the first triode and the first diode are connected in parallel; the second switching unit includes: the second triode and the second diode are connected in parallel; the third switching unit includes: the third triode and the third diode are connected in parallel; the fourth switching unit includes: the fourth triode and the fourth diode are connected in parallel.

4. The motor drive circuit of claim 3, wherein the first triode is connected with a first pull-up resistor; the control end of the second triode is connected with a second pull-up resistor; the control end of the third triode is connected with the first pull-down resistor; and the control end of the fourth triode is connected with the second pull-down resistor.

5. The motor drive circuit according to claim 1, wherein the first control unit includes a fifth transistor; the input end of the fifth triode is connected with the control end of the first switch unit; the second control unit comprises a sixth triode; the input end of the sixth triode is connected with the control end of the second switch unit; and the output ends of the fifth triode and the sixth triode are grounded.

6. The motor drive circuit according to claim 1, wherein the first delay unit comprises: the first end of the first delay resistor is configured to be connected with a first control signal, and the second end of the first delay resistor is connected with the control ends of the first control unit and the fourth switch unit; the second end of the first delay resistor is connected with the first end of the first capacitor; the second end of the first capacitor is grounded; the second delay unit includes: a second delay resistor and a second capacitor, wherein a first end of the second delay resistor is configured to be connected with a second control signal, and a second end of the second delay resistor is connected with control ends of the second control unit and the third switch unit; the second end of the second delay resistor is connected with the first end of the second capacitor; and the second end of the second capacitor is grounded.

7. The motor drive circuit according to claim 6, further comprising: a fifth diode and a sixth diode; a first end of the fifth diode is connected with a first end of the first capacitor, and a second end of the fifth diode is connected with control ends of the first control unit and the fourth switch unit; a first end of the sixth diode is connected to a first end of the second capacitor, and a second end of the sixth diode is connected to control ends of the second control unit and the third switching unit.

8. The motor drive circuit according to claim 6, further comprising: a first discharge cell and a second discharge cell; the input end of the first discharging unit is connected with the first end of the first capacitor, the output end of the first discharging unit is grounded, and the control end of the first discharging unit is configured to be connected with a second control signal; the input end of the second discharging unit is connected with the first end of the second capacitor, the output end of the second discharging unit is grounded, and the control end of the second discharging unit is configured to be connected with a first control signal.

9. The motor drive circuit according to claim 8, wherein the first discharge unit includes: the input end of the seventh triode is connected with the first end of the first capacitor, the output end of the seventh triode is grounded, and the control end of the seventh triode is configured to be connected with a second control signal; the second discharge unit includes: and the input end of the eighth triode is connected with the first end of the second capacitor, the output end of the eighth triode is grounded, and the control end of the eighth triode is configured to be connected with a first control signal.

10. A voice coil motor of a camera module, which is driven by the motor driving circuit according to any one of claims 1 to 9.

Technical Field

The invention relates to the technical field of motor driving, in particular to a motor driving circuit and a voice coil motor.

Background

A Voice Coil Motor (VCM) belongs to a linear dc Motor. At present, the voice coil motor is widely applied to the camera module, and the zooming function of the camera module can be realized through the upward pushing and the downward pushing of the voice coil motor. When the voice coil motor is used in the camera module, the driving chip is generally adopted to drive and control the voice coil motor. However, the manufacturing cost of the driving chip is high, and the manufacturing chain is long. When the sudden factor causes impact on the chip industry chain, the situation that the price of the driving chip fluctuates greatly or the goods are out of stock is easily caused, and further the shipment volume of terminals such as mobile phones and the like is greatly influenced.

Therefore, the driving method of the voice coil motor by adopting the driving chip in the prior art has the problems of high cost and unstable supply.

Disclosure of Invention

In view of this, embodiments of the present invention provide a motor driving circuit and a voice coil motor, which are implemented by using a discrete device design, and can replace a driving chip to drive the voice coil motor, so as to effectively reduce the cost.

In a first aspect, the present application provides the following technical solutions through an embodiment:

a motor driving circuit comprising: the first switch unit, the second switch unit, the third switch unit, the fourth switch unit, the first control unit, the second control unit, the first delay unit and the second delay unit;

the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the motor form an H-bridge circuit; the input end of the first control unit is connected with the control end of the first switch unit; the input end of the second control unit is connected with the control end of the second switch unit; the first end of the first delay unit is configured to be connected with a first control signal, and the second end of the first delay unit is connected with the control ends of the first control unit and the fourth switch unit; the first end of the second delay unit is configured to be connected with a second control signal, and the second end of the second delay unit is connected with the control ends of the second control unit and the third switch unit; the first control signal and the second control signal are opposite control signals.

Optionally, a first end of the first switch unit is connected to an input voltage, and a second end of the first switch unit is connected to a first end of the third switch unit; the first end of the second switch unit is connected with an input voltage, and the second end of the second switch unit is connected with the first end of the fourth switch unit; the first end of the motor is connected between the first switching unit and the third switching unit, and the second end of the motor is connected between the second switching unit and the fourth switching unit.

Optionally, the first switch unit includes: the first triode and the first diode are connected in parallel; the second switching unit includes: the second triode and the second diode are connected in parallel; the third switching unit includes: the third triode and the third diode are connected in parallel; the fourth switching unit includes: the fourth triode and the fourth diode are connected in parallel.

Optionally, the first triode is connected with a first pull-up resistor; the control end of the second triode is connected with a second pull-up resistor; the control end of the third triode is connected with the first pull-down resistor; and the control end of the fourth triode is connected with the second pull-down resistor.

Optionally, the first control unit includes a fifth triode; the input end of the fifth triode is connected with the control end of the first switch unit; the second control unit comprises a sixth triode; the input end of the sixth triode is connected with the control end of the second switch unit; and the output ends of the fifth triode and the sixth triode are grounded.

Optionally, the first delay unit includes: the first end of the first delay resistor is configured to be connected with a first control signal, and the second end of the first delay resistor is connected with the control ends of the first control unit and the fourth switch unit; the second end of the first delay resistor is connected with the first end of the first capacitor; the second end of the first capacitor is grounded; the second delay unit includes: a second delay resistor and a second capacitor, wherein a first end of the second delay resistor is configured to be connected with a second control signal, and a second end of the second delay resistor is connected with control ends of the second control unit and the third switch unit; the second end of the second delay resistor is connected with the first end of the second capacitor; and the second end of the second capacitor is grounded.

Optionally, the method further includes: a fifth diode and a sixth diode; a first end of the fifth diode is connected with a first end of the first capacitor, and a second end of the fifth diode is connected with control ends of the first control unit and the fourth switch unit; a first end of the sixth diode is connected to a first end of the second capacitor, and a second end of the sixth diode is connected to control ends of the second control unit and the third switching unit.

Optionally, the method further includes: a first discharge cell and a second discharge cell; the input end of the first discharging unit is connected with the first end of the first capacitor, the output end of the first discharging unit is grounded, and the control end of the first discharging unit is configured to be connected with a second control signal; the input end of the second discharging unit is connected with the first end of the second capacitor, the output end of the second discharging unit is grounded, and the control end of the second discharging unit is configured to be connected with a first control signal.

Optionally, the first discharge unit includes: the input end of the seventh triode is connected with the first end of the first capacitor, the output end of the seventh triode is grounded, and the control end of the seventh triode is configured to be connected with a second control signal; the second discharge unit includes: and the input end of the eighth triode is connected with the first end of the second capacitor, the output end of the eighth triode is grounded, and the control end of the eighth triode is configured to be connected with a first control signal.

In a second aspect, based on the same inventive concept, the present application provides the following technical solutions through an embodiment:

a voice coil motor of a camera module is driven by the motor driving circuit of any one of the first aspect.

A motor driving circuit provided in an embodiment of the present application includes: the first switch unit, the second switch unit, the third switch unit, the fourth switch unit, the first control unit, the second control unit, the first delay unit and the second delay unit; the first switch unit, the second switch unit, the third switch unit, the fourth switch unit and the motor form an H-bridge circuit; the input end of the first control unit is connected with the control end of the first switch unit; the input end of the second control unit is connected with the control end of the second switch unit; the first end of the first delay unit is configured to be connected with a first control signal, and the second end of the first delay unit is connected with the control ends of the first control unit and the fourth switch unit; the first end of the second delay unit is configured to be connected with a second control signal, and the second end of the second delay unit is connected with the control ends of the second control unit and the third switch unit; the first control signal and the second control signal are opposite control signals. The first control unit and the second control unit respectively carry out reverse phase control on the first switch unit and the second switch unit so as to realize the simultaneous opening or closing of the first switch unit and the third switch unit; at the same time, the second switching unit and the fourth switching unit are simultaneously turned off or on, so that the motor can be driven from both directions. Therefore, the motor driving circuit can be realized by adopting a discrete device design, and has higher driving reliability; can be applied to and drive voice coil motor on the camera module to the realization is to chip driven substitution, but effectual reduce cost, discrete device's supply of material is also more stable.

In order to make the aforementioned and other objects, features and advantages of the present invention comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.

Fig. 1 is a schematic structural diagram of a motor driving circuit according to a preferred embodiment of the present invention;

fig. 2 is a schematic diagram of a specific implementation of the motor driving circuit in fig. 1.

Detailed Description

In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.

Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. The terms "first," "second," "third," and the like are used solely to distinguish one from another and are not to be construed as indicating or implying relative importance.

Referring to fig. 1, the present embodiment provides a motor driving circuit 100, including: a first switching unit 101, a second switching unit 102, a third switching unit 103, a fourth switching unit 104, a first control unit 201, a second control unit 202, a first delay unit 301, and a second delay unit 302.

The first switching unit 101, the second switching unit 102, the third switching unit 103, the fourth switching unit 104, and the motor M1 constitute an H-bridge circuit. Specifically, a first terminal of the first switching unit 101 is connected to an input voltage, and a second terminal of the first switching unit 101 is connected to a first terminal of the third switching unit 103; the first end of the second switch unit 102 is connected to the input voltage, and the second end of the second switch unit 102 is connected to the first end of the fourth switch unit 104; the first switch unit 101 and the third switch unit 103 are connected with the first end of the motor M1, and the second switch unit 102 and the fourth switch unit 104 are connected with the second end of the motor M1; the output terminals of the third switching unit 103 and the fourth switching unit 104 are both grounded.

When the four switch units are in the first state, the connected motor M1 can be rotated or driven towards the first direction after a loop is formed; the first state is: the second and third switching units 102 and 103 are both turned off, and the first and fourth switching units 101 and 104 are both turned on. When the four switch units are in the second state, the connected motor M1 can be rotated or driven towards the second direction after a loop is formed; the second state is: when the first switching unit 101 and the fourth switching unit 104 are both turned off, and the second switching unit 102 and the third switching unit 103 are both turned on. Motor M1 may be a voice coil motor on the camera module, such as voice coil motor VCM shown in fig. 2; the first direction may be a push-up direction, the second direction may be a push-down direction, and the driving of the voice coil motor may be realized by the motor driving circuit 100 described above, and may replace the chip control.

Further, the input end of the first control unit 201 is connected with the control end of the first switch unit 101; the input end of the second control unit 202 is connected with the control end of the second switch unit 102; a first end of the first delay unit 301 is configured to be connected to the first control signal, and a second end of the first delay unit 301 is connected to the control ends of the first control unit 201 and the fourth switch unit 104; a first end of the second delay unit 302 is configured to be connected with a second control signal, and a second end of the second delay unit 302 is connected with control ends of the second control unit 202 and the third switching unit 103; the first control signal and the second control signal are opposite control signals. The drive control of the motor M1 is realized by the control of the first control signal and the second control signal, and the inversion of the first control unit 201 and the second control unit 202 according to different control signals, so that the four switch units can reach the first state or the second state.

Referring to fig. 2, the first switch unit 101 may include: the first triode Q1 is connected with a first diode, and the first triode Q1 is connected with a first diode D1 in parallel; the second switching unit 102 includes: the second triode Q2 and the second diode D2 are connected in parallel, and the second triode Q2 and the second diode D2 are connected in parallel; the third switching unit 103 includes: the third triode Q3 is connected with a third diode D3, and the third triode Q3 is connected with a third diode D3 in parallel; the fourth switching unit 104 includes: the fourth transistor Q4 is connected in parallel with the fourth diode D4, and the fourth transistor Q4 is connected in parallel with the fourth diode D4. The first diode D1, the second diode D2, the third diode D3 and the fourth diode D4 can be used as freewheeling diodes, and the induced current generated during the turn-off period of the motor M1 forms a loop with the freewheeling diodes, thereby preventing the triode from being damaged.

In order to ensure that the four switch units can be correctly opened and closed, loops with two current directions are formed. The first triode Q1 can be connected with a first pull-up resistor R1, the control end of the second triode Q2 is connected with a second pull-up resistor R2, the control end of the third triode Q3 is connected with a first pull-down resistor R3, and the control end of the fourth triode Q4 is connected with a second pull-down resistor R4; when the first transistor Q1 and the fourth transistor Q4 are turned on and the second transistor Q2 and the third transistor Q3 are turned off, a first directional current flowing through the motor M1 may be formed; conversely, when the first transistor Q1 and the fourth transistor Q4 are turned off, and the second transistor Q2 and the third transistor Q3 are turned off, a second direction current flowing through the motor M1 is formed, and the first direction and the second direction are opposite directions, so that the driving of the motor M1 is completed in two directions.

A first control unit 201 and a second control unit 202 for inverting the input control signal. Specifically, the same control signal is used for realizing opposite control effects on the two switch units. Specifically, the first control unit 201 includes a fifth transistor Q5, and an input terminal of the fifth transistor Q5 is connected to the control terminal of the first switch unit 101, that is, the control terminal of the first transistor Q1. The second control unit 202 includes a sixth triode, and an input terminal of the sixth triode is connected to the control terminal of the second switching unit 102, that is, the control terminal of the second triode Q2; the output terminals of the fifth transistor Q5 and the sixth transistor Q6 are grounded. The control end of the fifth triode Q5 is connected with the third pull-down resistor R10, and the control end of the sixth triode Q6 is connected with the fourth pull-down resistor R9. For example, when the fifth transistor Q5 is controlled to be turned on, the control terminal of the first transistor Q1 may be set to a low level, and when the fifth transistor Q5 is turned off, the control terminal of the first transistor Q1 may be set to a high level, so as to control the first transistor Q1; similarly, it can be determined that the control of the second transistor Q2 is achieved by turning the sixth transistor Q6 on and off.

The first delay unit 301 and the second delay unit 302 are configured to implement full conduction of the transistors in the H-bridge circuit, and ensure that the motor M1 is turned on after all four transistors are turned off. For example, the triode is prevented from being in an amplifying state when the shutdown motor M1 pushes up, and is directly communicated with the lower triode to be short-circuited, so that the triode is prevented from being damaged.

Specifically, the first delay unit 301 and the second delay unit 302 may be both formed of RC circuits. The first delay unit 301 includes: a first delay resistor R13 and a first capacitor C11, a first end of the first delay resistor R13 is configured to be connected to the first control signal, and a second end of the first delay resistor R13 is connected to the control ends of the first control unit 201 and the fourth switching unit 104, that is, the control ends of the fifth transistor Q5 and the fourth transistor Q4. The second terminal of the first delay resistor R13 is connected to the first terminal of the first capacitor C11, and the second terminal of the first capacitor C11 is grounded. The second delay unit 302 includes: a second delay resistor R14 and a second capacitor C12, a first end of the second delay resistor R14 is configured to receive the second control signal, and a second end of the second delay resistor R14 is connected to the control ends of the second control unit 202 and the third switching unit 103, that is, the control ends of the sixth transistor Q6 and the third transistor Q3. The second end of the second delay resistor R14 is connected with the first end of the second capacitor C12; the second terminal of the second capacitor C12 is connected to ground. In different products, due to the performance difference of the voice coil motor, the triode and the like, the response time of the voice coil motor is different. Therefore, the delay time may be different in different products in this embodiment, and the delay time of different products can be determined through testing or theoretical calculation. The delay time can be calculated according to a capacitance charging formula to match the value of the resistance and the capacitance, t is RC In (V/V-U), the time constant tau of RC, V is the input voltage, and U is the charging voltage on the capacitance at the moment t.

Further, a voltage stabilizing circuit may be added based on the above-mentioned delay circuit, that is, the motor driving circuit 100 further includes: a fifth diode D5 and a sixth diode D6 as zener diodes. A first terminal of the fifth diode D5 is connected to the first terminal of the first capacitor C11, and a second terminal of the fifth diode D5 is connected to the control terminals of the first control unit 201 and the fourth switching unit 104, that is, the control terminals of the fifth transistor Q5 and the fourth transistor Q4. A first end of the sixth diode D6 is connected to the first end of the second capacitor C12, and a second end of the sixth diode D6 is connected to the control ends of the second control unit 202 and the third switching unit 103, that is, the control ends of the sixth transistor Q6 and the third transistor Q3.

When the motor driving circuit 100 is applied to a camera module, the push-up or push-down response time of the voice coil motor is short. In order to ensure that the voice coil motor can respond to the pushing in two directions quickly, in this embodiment, the motor driving circuit 100 may further include: a first discharge cell 401 and a second discharge cell 402. The input end of the first discharge unit 401 is connected to the first end of the first capacitor C11, the output end of the first discharge unit 401 is grounded, and the control end of the first discharge unit 401 is configured to be connected to the second control signal; the input terminal of the second discharge unit 402 is connected to the first terminal of the second capacitor C12, the output terminal of the second discharge unit 402 is connected to ground, and the control terminal of the second discharge unit 402 is configured as a first control signal.

Further, the first discharge unit 401 includes: an input end of the seventh triode Q7 and an input end of the seventh triode Q7 are connected with the first end of the first capacitor C11, an output end of the seventh triode Q7 is grounded, and a control end of the seventh triode Q7 is configured to be connected with the second control signal. The second discharge unit 402 includes: and an eighth transistor Q8, wherein an input terminal of the eighth transistor Q8 is connected to the first terminal of the second capacitor C12, an output terminal of the eighth transistor Q8 is connected to ground, and a control terminal of the eighth transistor Q8 is configured to be connected to the first control signal. The control end of the seventh triode Q7 is connected with the fifth pull-down resistor R15, and the control end of the eighth triode Q8 is connected with the sixth pull-down resistor R16.

The first discharging unit 401 can quickly discharge the charges in the first capacitor C11, and ensure that the first transistor Q1 and the fourth transistor Q4 are quickly and completely disconnected; or the second discharging unit 402 can quickly discharge the charges in the second capacitor C12, so as to ensure that the second transistor Q2 and the third transistor Q3 are quickly and completely disconnected. When the rotation or pushing direction of the motor M1 is switched, a quick response is achieved.

In this embodiment, the first transistor Q1 and the second transistor Q2 may be PNP transistors, and the third transistor Q3, the fourth transistor Q4, the fifth transistor Q5, the sixth transistor Q6, the seventh transistor Q7, and the eighth transistor Q8 may be NPN transistors. For a PNP type triode, the control terminal in this embodiment is a base, the input terminal is an emitter, and the output terminal is a collector; for an NPN type transistor, the control terminal is a base, the input terminal is a collector, and the output terminal is an emitter.

With reference to fig. 2, a specific example is provided in the present embodiment.

Wherein, AF _ UP represents a first control signal, and AF _ DOWN represents a second control signal; when the AF _ UP input is a high level signal, the AF _ DOWN is a low level signal. After the AF _ UP is input with a high level, the high level is connected to the base electrode of the fifth triode Q5 through the delay circuit, the voltage stabilizing circuit and the resistor R12. At this time, since AF _ DOWN is a low level signal, the seventh triode is controlled to be turned off after passing through the resistor R18; the base of the fifth triode Q5 is at high level, and the fifth triode Q5 is conducted; the base of the first triode Q1 is grounded through the resistor R5 and the fifth triode Q5, the base of the first triode Q1 is at low level, and the base of the first triode Q1 is conducted. Meanwhile, after the AF _ UP inputs a high level, the high level is connected to the base of the fourth triode Q4 through the delay circuit, the voltage stabilizing circuit and the resistor R8, and the base of the fourth triode Q4 is turned on at a high level.

Correspondingly, the AF _ DOWN inputs a low level signal, passes through the delay circuit and the voltage stabilizing circuit, and is connected to the base of the third triode Q3 through the resistor R7. The base of the third triode Q3 is at low level, and the third triode Q3 is closed; meanwhile, after the AF _ DOWN inputs a low level, the low level is connected to the base electrode of the sixth triode Q6 through the delay circuit, the voltage stabilizing circuit and the resistor R11. At this time, the AF _ UP input is a low level signal, and the eighth triode is controlled to be turned off after passing through the resistor R17; the base of the sixth transistor Q6 is low and the sixth transistor Q6 is off. The second transistor Q2 is disconnected by the sixth transistor Q6 through the grounded line of the resistor R6, the base of the second transistor Q2 is at the switched-in operating voltage (AFVDD _3.3V), and the second transistor Q2 is disconnected.

That is, when the AF _ UP input is a high level signal and the AF _ DOWN input is a low level signal, the second transistor Q2 and the third transistor Q3 are turned off; the first transistor Q1 and the fourth transistor Q4 are open and a path is formed and the motor M1 is turned or pushed in a first direction. When the AF _ UP input is a low level signal and the AF _ DOWN input is a high level signal, derivation can be performed according to the above inference process, which is not described in detail in this embodiment.

In the example shown in fig. 2, the various resistor, capacitor, and transistor types and parameters are labeled as merely one implementation. In different embodiments, corresponding adaptations or alternatives may be made.

The product according to fig. 2 is produced, and after material procurement and production, the cost of each driving circuit can be generally guaranteed to be less than 5 yuan. If the driving chips with the same functions are adopted, the cost of each chip is more than 10 yuan, and the cost is greatly fluctuated in different periods, so that the cost of using the chip driving is higher. Therefore, compared with the chip with the same function, the driving circuit of the embodiment can effectively reduce the cost by at least 50%, and the supply of discrete devices is more stable. According to the shipping volume of tens of millions of grades, billions of grades of camera module producer, when guaranteeing that the function realizes, adopt the improvement cost advantage that motor drive circuit 100 of this embodiment can show.

In summary, the motor driving circuit 100 provided in the present embodiment includes: a first switching unit 101, a second switching unit 102, a third switching unit 103, a fourth switching unit 104, a first control unit 201, a second control unit 202, a first delay unit 301, and a second delay unit 302; the first switching unit 101, the second switching unit 102, the third switching unit 103, the fourth switching unit 104 and the motor M1 constitute an H-bridge circuit; the input end of the first control unit 201 is connected with the control end of the first switch unit 101; the input end of the second control unit 202 is connected with the control end of the second switch unit 102; a first end of the first delay unit 301 is configured to be connected to the first control signal, and a second end of the first delay unit 301 is connected to the control ends of the first control unit 201 and the fourth switch unit 104; a first end of the second delay unit 302 is configured to be connected with a second control signal, and a second end of the second delay unit 302 is connected with control ends of the second control unit 202 and the third switching unit 103; the first control signal and the second control signal are opposite control signals. Therefore, the motor driving circuit 100 can be realized by adopting a discrete device design and has higher driving reliability; can be applied to and drive voice coil motor on the camera module to the realization is to chip driven substitution, but effectual reduce cost, discrete device's supply of material is also more stable.

In another embodiment of the present invention, a voice coil motor is further provided, and the voice coil motor is driven by using the motor driving circuit 100 in the foregoing embodiment. Therefore, the voice coil motor driven by the motor driving circuit 100 has the characteristics of low cost and reliable production and distribution.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.