Motor driving circuit with reverse current detection mechanism

Abstract

The invention discloses a motor driving circuit with a reverse current detection mechanism. The invention discloses a motor driving circuit with a reverse current detection mechanism. The motor driving circuit comprises a reverse current detection circuit, a control circuit, a driving circuit and an output stage circuit, the reverse current detection circuit detects a current flowing through the motor within a default time interval to output a current detection signal. The control circuit determines whether the detected current is a reverse current according to the current detection signal so as to output a control signal. The driving circuit outputs a driving signal according to the control signal. The output stage circuit operates according to the driving signal so as to output an output stage signal to the motor. The motor operates according to the output stage signal.

Description

Technical Field

[0001] The present invention relates to a motor driving circuit, and in particular to a motor driving circuit with a reverse current detection mechanism. Background Art

[0002] The circuit components of electronic products will generate heat during operation. Specifically, in the closed casing of a server or other closed space, the heat generated by each circuit component during operation will circulate in the closed casing, heating other circuit components and causing overheating and damage to the circuit components. Therefore, fans must be installed in electronic products to cool the circuit components of the electronic products.

[0003] However, in the fan, when the control circuit controls the multiple transistors of the motor driving circuit to operate to drive the motor to rotate, a reverse current will be generated to flow through the motor and the multiple transistors of the motor driving circuit, affecting the operation of the motor. Summary of the invention

[0004] The technical problem to be solved by the present invention is to provide a motor drive circuit with a reverse current detection mechanism in view of the shortcomings of the prior art, which is suitable for a motor. The motor drive circuit with a reverse current detection mechanism comprises a reverse current detection circuit, a control circuit, a drive circuit and an output stage circuit. The reverse current detection circuit is connected to the motor. The reverse current detection circuit is configured to detect the current flowing through the motor within a default time interval to output a current detection signal. The control circuit is connected to the reverse current detection circuit. The control circuit is configured to determine whether a reverse current flows through the motor according to the current detection signal, determine a control signal accordingly, and output the control signal. The drive circuit is configured to output a drive signal according to the control signal. The output stage circuit connects the drive circuit and the motor. The output stage circuit is configured to operate according to the drive signal to output an output stage signal to the motor. The motor operates according to the output stage signal. The motor operates according to the output stage signal.

[0005] In an embodiment, the output stage circuit includes a plurality of upper bridge transistors and a plurality of lower bridge transistors. The plurality of upper bridge transistors include a first upper bridge transistor and a second upper bridge transistor. The first end of the first upper bridge transistor and the first end of the second upper bridge transistor are coupled to a common voltage. The plurality of lower bridge transistors include a first lower bridge transistor and a second lower bridge transistor. The first end of the first lower bridge transistor is connected to the second end of the first upper bridge transistor. The first end of the second lower bridge transistor is connected to the second end of the second upper bridge transistor. The second end of the first lower bridge transistor and the second end of the second lower bridge transistor are grounded. The control end of each of the transistors is connected to the output end of the drive circuit. The first end of the motor is connected to a node between the first end of the first lower bridge transistor and the second end of the first upper bridge transistor. The second end of the motor is connected to a node between the first end of the second lower bridge transistor and the second end of the second upper bridge transistor.

[0006] In an embodiment, when the control circuit determines that a reverse current flows through the motor, the control circuit controls the driving circuit to turn off any one of the plurality of lower bridge transistors.

[0007] In an embodiment, the driving circuit keeps turning off any one of the plurality of lower bridge transistors for a period of time until the motor switches phases, and then resumes normal operation of turning on each of the upper bridge transistors and each of the lower bridge transistors in turn.

[0008] In an embodiment, the reverse current detection circuit is connected to the first end, the second end, the third end or any combination thereof of the motor. The control circuit determines whether a reverse current flows through the motor according to the voltage of the first end, the second end, the third end or any combination thereof of the motor detected by the reverse current detection circuit.

[0009] In an embodiment, the reverse current detection circuit is connected to the first end, the second end, the third end or any combination thereof of the motor. The control circuit compares the voltage of the first end, the second end, the third end or any combination thereof of the motor detected by the reverse current detection circuit with a reference voltage to determine whether a reverse current flows through the motor.

[0010] In an embodiment, the reverse current detection circuit is connected to an anode or cathode of a body diode of any one of the plurality of lower bridge transistors. The control circuit determines whether a reverse current flows through the motor according to the current flowing through the body diode of any one of the plurality of lower bridge transistors detected by the reverse current detection circuit.

[0011] In an embodiment, the reverse current detection circuit is connected to an anode and a cathode of a body diode of any one of the plurality of lower bridge transistors. The reverse current detection circuit is configured to detect a voltage of the body diode of any one of the plurality of lower bridge transistors. The control circuit determines whether the body diode is turned on according to the voltage of the body diode of any one of the plurality of lower bridge transistors detected by the reverse current detection circuit, thereby determining whether a reverse current flows through the motor.

[0012] In an embodiment, the reverse current detection circuit is connected to an anode and a cathode of a body diode of any one of the plurality of lower bridge transistors. The reverse current detection circuit is configured to detect a voltage of the body diode of any one of the plurality of lower bridge transistors and calculate a difference between the voltage of the body diode and a reference voltage. The control circuit determines whether a reverse current flows through the motor according to the difference between the voltage of the body diode and the reference voltage.

[0013] In an embodiment, the reverse current detection circuit is connected to the first end and the second end of any one of the plurality of lower bridge transistors. The reverse current detection circuit is configured to detect the voltage of the first end and the second end of any one of the plurality of lower bridge transistors and calculate the voltage difference between the first end and the second end of any one of the plurality of lower bridge transistors. The control circuit determines whether a reverse current flows through the motor according to the voltage difference between the first end and the second end of any one of the plurality of lower bridge transistors received from the reverse current detection circuit.

[0014] In an embodiment, the reverse current detection circuit comprises an operational amplifier, a first input terminal of the operational amplifier is coupled to a voltage difference between an anode and a cathode of a body diode of any one of the plurality of lower bridge transistors, a second input terminal of the operational amplifier is coupled to a reference voltage, and an output terminal of the operational amplifier is coupled to an input terminal of the control circuit, and the control circuit determines whether a reverse current flows through the motor according to an operational amplification signal received from the operational amplifier.

[0015] In an embodiment, the reverse current detection circuit comprises an operational amplifier. A first input terminal of the operational amplifier is coupled to a first terminal, a second terminal or a third terminal of the motor. A second input terminal of the operational amplifier is coupled to a reference voltage. An output terminal of the operational amplifier is coupled to an input terminal of the control circuit. The control circuit determines whether a reverse current flows through the motor according to an operational amplification signal received from the operational amplifier.

[0016] In an embodiment, the motor is a single-phase motor.

[0017] In an embodiment, the motor is a three-phase motor.

[0018] In an embodiment, a rotor position detection circuit is connected to the motor and the control circuit. The rotor position detection circuit is configured to detect the rotor position of the motor to output a rotor position detection signal. The control circuit controls the drive circuit according to the rotor position detection signal received from the rotor position detection circuit.

[0019] As described above, the present invention provides a motor drive circuit with a reverse current detection mechanism. The motor drive circuit with a reverse current detection mechanism of the present invention detects whether a reverse current (or back electromotive force current) flows through the motor within a predetermined time interval, and switches the lower bridge transistor (and / or the upper bridge transistor) when a reverse current is detected flowing through the motor to prevent abnormal operation of the motor and generate noise.

[0020] To further understand the features and technical contents of the present invention, please refer to the following detailed description and drawings of the present invention. However, the drawings provided are only for reference and description and are not intended to limit the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 FIG. 4 is a block diagram of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0022] Figure 2 FIG. 4 is a circuit diagram of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0023] Figure 3 The figure is a schematic diagram of current flow during the switching process of multiple transistors in the output stage circuit of the motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0024] Figure 4 FIG. 4 is a waveform diagram of signals of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0025] Figure 5 The figure is a schematic diagram of current flow during the switching process of multiple transistors in the output stage circuit of the motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0026] Figure 6 FIG. 4 is a waveform diagram of signals of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0027] Figure 7 The diagram is a schematic diagram of a reverse current flowing through a body diode in an output stage circuit of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0028] Figure 8 FIG. 4 is a circuit diagram of a reverse current detection circuit of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The following is an explanation of the embodiments of the present invention through specific embodiments. Those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in this specification. The present invention can be implemented or applied through other different specific embodiments, and the details in this specification can also be modified and changed in various ways based on different viewpoints and applications without departing from the concept of the present invention. In addition, the drawings of the present invention are only simple schematic illustrations and are not depicted according to actual dimensions. It is stated in advance. The following embodiments will further explain the relevant technical contents of the present invention in detail, but the disclosed contents are not intended to limit the scope of protection of the present invention. In addition, the term "or" used herein may include any one or more combinations of the associated listed items depending on the actual situation.

[0030] See also Figure 1 , Figure 2 and Figure 4 ,in Figure 1 is a block diagram of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention, Figure 2 is a circuit diagram of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention; Figure 4 FIG. 4 is a waveform diagram of signals of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0031] The motor driving circuit with reverse current detection mechanism of the present invention is suitable for driving a motor MT, such as a single-phase motor or a three-phase motor.

[0032] The motor drive circuit with reverse current detection mechanism of the present invention comprises the following Figure 1 The reverse current detection circuit 10, the control circuit 20, the drive circuit 30 and the output stage circuit 40 are shown. If necessary, the motor drive circuit of the present invention may also include the following Figure 1 The rotor position detection circuit 50 is shown.

[0033] The reverse current detection circuit 10 is connected to the motor MT. The control circuit 20 is connected to the reverse current detection circuit 10, the drive circuit 30, and the rotor position detection circuit 50. The output stage circuit 40 is connected to the drive circuit 30 and the motor MT.

[0034] The output stage circuit 40 may include a plurality of upper bridge transistors such as Figure 2 The first upper bridge transistor H1 and the second upper bridge transistor H2, as well as the plurality of lower bridge transistors, are shown. Figure 2The illustrated embodiment includes a first lower bridge transistor L1 and a second lower bridge transistor L2 .

[0035] like Figure 2 As shown, the first end of the first upper bridge transistor H1 and the first end of the second upper bridge transistor H2 are coupled to a common voltage VCC. The first end of the first lower bridge transistor L1 is connected to the second end of the first upper bridge transistor H1. The first end of the second lower bridge transistor L2 is connected to the second end of the second upper bridge transistor H2. The second end of the first lower bridge transistor L1 and the second end of the second lower bridge transistor L2 are grounded.

[0036] like Figure 2 As shown, the first terminal OUT1 of the motor MT is connected to the node between the first terminal of the first lower bridge transistor L1 and the second terminal of the first upper bridge transistor H1. The second terminal OUT2 of the motor MT is connected to the node between the first terminal of the second lower bridge transistor L2 and the second terminal of the second upper bridge transistor H2. The signal of the first terminal OUT1 of the motor MT can be, for example, as follows Figure 4 The first signal OUTS1 and the second signal OUTS2 at the second end OUT2 of the motor MT change accordingly.

[0037] If the motor MT is a three-phase motor, the third terminal OUT3 of the motor MT can be connected to the output stage circuit 40. The output stage circuit 40 also includes a third upper bridge transistor and a third lower bridge transistor. The third terminal OUT3 of the motor MT is connected to a node between the second terminal of the third upper bridge transistor and the first terminal of the third lower bridge transistor. The first terminal of the third upper bridge transistor is coupled to a common voltage VCC. The second terminal of the third upper bridge transistor H3 is connected to the first terminal of the third lower bridge transistor L3. The second terminal of the third lower bridge transistor L3 is grounded.

[0038] Each transistor (eg Figure 2 The control ends of the first upper bridge transistor H1 , the second upper bridge transistor H2 , the first lower bridge transistor L1 , and the second lower bridge transistor L2 are connected to the output end of the driving circuit 30 .

[0039] The control circuit 20 may output a rotor position detection signal according to the position of the rotor of the motor MT detected by the rotor position detection circuit 50 and the Figure 4 The pulse width modulation signal PWM shown in FIG. 1 controls the driving circuit 30 to drive each transistor of the output stage circuit 40 (eg, Figure 2 The first upper bridge transistor H1, the second upper bridge transistor H2, the first lower bridge transistor L1 and the second lower bridge transistor L2 are operated to run the motor MT.

[0040] When the motor MT is running, the reverse current detection circuit 10 can detect the current IL flowing through the motor MT within a preset time interval to output a current detection signal to the control circuit 20. For example, the reverse current detection circuit 10 detects the current IL flowing through the motor MT within a predetermined time after a period of time has passed since the motor MT was switched to output a current detection signal to the control circuit 20.

[0041] If the motor MT driven by the motor driving circuit of the present invention is a three-phase motor, the reverse current detection circuit 10 can detect the current flowing through any one or more of the first end OUT1 (for example, the U-phase end), the second end OUT2 (for example, the V-phase end) and the third end (for example, the W-phase end) of the three-phase motor MT to output a current detection signal to the control circuit 20.

[0042] The control circuit 20 may determine whether the current detected by the reverse current detection circuit 10 is a reverse current according to the current detection signal received from the reverse current detection circuit 10 , and accordingly determine or adjust the control signal output to the driving circuit 30 .

[0043] The driving circuit 30 outputs a driving signal to the output stage circuit 40 (eg, each transistor of the output stage circuit 40) according to the control signal received from the control circuit 20. Figure 2 The control ends of the first upper bridge transistor H1, the second upper bridge transistor H2, the first lower bridge transistor L1 and the second lower bridge transistor L2 are shown).

[0044] The output stage circuit 40 (multiple transistors such as Figure 2 The first upper transistor H1, the second upper transistor H2, the first lower transistor L1 and the second lower transistor L2 are operated according to the driving signal received from the driving circuit 30 to output an output signal to the motor MT. The motor MT operates according to the output signal received from the output circuit 40.

[0045] See also Figures 2 to 6 ,in Figure 3 FIG. 1 is a schematic diagram of current flow during switching of multiple transistors in an output stage circuit of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention. Figure 5 FIG. 1 is a schematic diagram of current flow during switching of multiple transistors in an output stage circuit of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention. Figure 6 FIG. 4 is a waveform diagram of signals of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0046] like Figure 2 The driving circuit 30 of the motor driving circuit of the present invention can be as shown in FIG. Figure 3 (a) to Figure 3 (c) or Figure 5 (a) to Figure 5 As shown in (b), the first upper bridge transistor H1 and the first lower bridge transistor L1 are switched complementarily. That is, the driving circuit 30 switches the first lower bridge transistor L1 from the on state to the off state, and simultaneously switches the second lower bridge transistor L2 from the off state to the on state.

[0047] If the first lower bridge transistor L1 and the second lower bridge transistor L2 are switched, Figure 3 The reverse current (shown as a solid line in (c) Figure 4 or Figure 6 When the portion of the current IL that is reduced to below zero as shown in FIG. 1 is a reverse current) flows through the motor MT, the drive circuit 30 is as follows Figure 3 As shown in (d), the first lower bridge transistor L1 is turned off. As a result, the current flows sequentially through the second lower bridge transistor L2, the motor MT and the first upper bridge transistor H1 to the input power supply for supplying the common voltage VCC. In this way, the first lower bridge transistor L1 is prevented from being damaged by overcurrent, thereby affecting the operation of the motor MT.

[0048] When the control circuit 20 determines that a reverse current flows through the motor MT, the drive circuit 30 may Figure 3 As shown in (d), the first lower bridge transistor L1 is kept turned off for a period of time until the motor MT switches phases, and then the normal complementary switching of the first lower bridge transistor L1 and the first upper bridge transistor H1 is restored.

[0049] See also Figure 2 and Figure 7 ,in Figure 7 The diagram is a schematic diagram of a reverse current flowing through a body diode in an output stage circuit of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0050] The reverse current detection circuit 10 can be connected to the body diode of any one of the plurality of lower bridge transistors included in the output stage circuit 40, such as but not limited to: Figure 7 The anode (and cathode) of the body diode Dd of the second low bridge transistor L2 is shown.

[0051] The reverse current detection circuit 10 can detect the current flowing through the body diode Dd of the second lower bridge transistor L2 to output a current detection signal to the control circuit 20. The control circuit 20 determines whether there is a reverse current flowing through the motor MT according to the current detection signal received from the reverse current detection circuit 10, and determines the control signal output to the drive circuit 30 accordingly.

[0052] Additionally or alternatively, the reverse current detection circuit 10 may detect the voltage of the body diode Dd of the second lower bridge transistor L2 and output it to the control circuit 20. The control circuit 20 may determine whether a reverse current flows through the motor MT based on the voltage of the body diode Dd of the second lower bridge transistor L2 detected by the reverse current detection circuit 10, and accordingly determine the control signal output to the drive circuit 30.

[0053] If necessary, the reverse current detection circuit 10 can further compare the voltage Vd of the body diode Dd with a reference voltage Vref, or calculate the difference between the voltage Vd of the body diode Dd and a reference voltage Vref to determine whether a reverse current flows through the motor MT, thereby determining the control signal output to the drive circuit 30.

[0054] See also Figure 2 and Figure 8 ,in Figure 8 FIG. 4 is a circuit diagram of a reverse current detection circuit of a motor driving circuit with a reverse current detection mechanism according to an embodiment of the present invention.

[0055] For example, the reverse current detection circuit 10 of the motor driving circuit of the present invention may include: Figure 8 The operational amplifier 101 shown here is merely an example, and the present invention is not limited thereto.

[0056] like Figure 8 The first input terminal, for example, the non-inverting input terminal, of the operational amplifier 101 shown in the figure can be connected to any one of a plurality of lower bridge transistors (for example, but not limited to, Figure 7 The first end (eg, drain), the second end (eg, source), or the body diode of the second lower bridge transistor L2 shown in FIG. Figure 7 The anode (and cathode) of the body diode Dd is shown.

[0057] Alternatively, the first input terminal of the operational amplifier 101, such as the non-inverting input terminal, can be connected to one of the first terminal OUT1, the second terminal OUT2, and the third terminal OUT3 of the motor MT. In fact, the reverse current detection circuit 10 can include more operational amplifiers, whose first input terminals can be connected to the other two of the first terminal OUT1, the second terminal OUT2, and the third terminal OUT3 of the motor MT.

[0058] A second input terminal, such as a non-inverting input terminal, of the operational amplifier 101 is coupled to a reference voltage Vref. An output terminal of the operational amplifier 101 is connected to an input terminal of the driving circuit 30 .

[0059] The operational amplifier 101 multiplies the difference between the voltage at the first input terminal of the operational amplifier 101 and the voltage at the second input terminal of the operational amplifier 101 by a gain to output an operational amplification signal to the control circuit 20. The control circuit 20 can determine whether a reverse current flows through the motor MT according to the operational amplification signal received from the operational amplifier 101, and determine the control signal output to the driving circuit 30 accordingly.

[0060] In summary, the present invention provides a motor drive circuit with a reverse current detection mechanism. The motor drive circuit with a reverse current detection mechanism of the present invention detects whether a reverse current (or back electromotive force current) flows through the motor within a predetermined time interval, and switches the lower bridge transistor (and / or the upper bridge transistor) when a reverse current is detected flowing through the motor to prevent abnormal operation of the motor and generate noise.

[0061] The contents disclosed above are only preferred feasible embodiments of the present invention, and are not intended to limit the claims of the present invention. Therefore, all equivalent technical changes made using the description and drawings of the present invention are included in the claims of the present invention.

Claims

1. A motor drive circuit with a reverse current detection mechanism, suitable for a motor, characterized in that: The motor drive circuit with reverse current detection mechanism comprises: A reverse current detection circuit connected to the motor, wherein the reverse current detection circuit is configured to detect the current flowing through the motor within a default time interval to output a current detection signal; A control circuit connected to the reverse current detection circuit, the control circuit being configured to determine whether a reverse current flows through the motor according to the current detection signal, determine a control signal accordingly, and output the control signal; A driving circuit connected to the control circuit, wherein the driving circuit is configured to output a driving signal according to the control signal; as well as The output stage circuit is connected to the driving circuit and the motor. The output stage circuit is configured to operate according to the driving signal to output an output stage signal to the motor. The motor operates according to the output stage signal.

2. The motor driving circuit with reverse current detection mechanism according to claim 1, characterized in that: The output stage circuit comprises: A plurality of upper bridge transistors, including a first upper bridge transistor and a second upper bridge transistor, wherein a first end of the first upper bridge transistor and a first end of the second upper bridge transistor are coupled to a common voltage; as well as A plurality of lower bridge transistors, including a first lower bridge transistor and a second lower bridge transistor, wherein a first end of the first lower bridge transistor is connected to a second end of the first upper bridge transistor, a first end of the second lower bridge transistor is connected to a second end of the second upper bridge transistor, and a second end of the first lower bridge transistor and a second end of the second lower bridge transistor are grounded; Wherein the control end of each of the transistors is connected to the output end of the driving circuit; wherein the first end of the motor is connected to a node between the first end of the first lower bridge transistor and the second end of the first upper bridge transistor; The second end of the motor is connected to a node between the first end of the second lower bridge transistor and the second end of the second upper bridge transistor.

3. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: When the control circuit determines that a reverse current flows through the motor, the control circuit controls the driving circuit to turn off any one of the plurality of lower bridge transistors.

4. The motor driving circuit with reverse current detection mechanism according to claim 3, characterized in that: The driving circuit keeps turning off any one of the plurality of lower bridge transistors for a period of time until the motor switches phases, and then resumes normal operation of turning on each of the upper bridge transistors and each of the lower bridge transistors in turn.

5. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit is connected to the first end, the second end, the third end or any combination thereof of the motor, and the control circuit determines whether a reverse current flows through the motor based on the voltage of the first end, the second end, the third end or any combination thereof detected by the reverse current detection circuit.

6. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit is connected to the first end, the second end, the third end or any combination thereof of the motor, and the control circuit compares the voltage of the first end, the second end, the third end or any combination thereof of the motor detected by the reverse current detection circuit with a reference voltage to determine whether there is a reverse current flowing through the motor.

7. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit is connected to the anode or cathode of a body diode of any one of the multiple lower bridge transistors, and the control circuit determines whether a reverse current flows through the motor based on the current flowing through the body diode of any one of the multiple lower bridge transistors detected by the reverse current detection circuit.

8. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit is connected to an anode and a cathode of a body diode of any one of the plurality of lower bridge transistors, and the reverse current detection circuit is configured to detect a voltage of the body diode of any one of the plurality of lower bridge transistors; The control circuit determines whether the body diode of any one of the plurality of lower bridge transistors is turned on based on the voltage of the body diode detected by the reverse current detection circuit, thereby determining whether a reverse current flows through the motor.

9. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit is connected to an anode and a cathode of a body diode of any one of the plurality of lower bridge transistors, and the reverse current detection circuit is configured to detect a voltage of the body diode of any one of the plurality of lower bridge transistors, and calculate a difference between the voltage of the body diode and a reference voltage; The control circuit determines whether a reverse current flows through the motor according to a difference between a voltage of the body diode and the reference voltage.

10. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit is connected to the first terminal and the second terminal of any one of the plurality of lower bridge transistors, and the reverse current detection circuit is configured to detect the voltage of the first terminal and the second terminal of any one of the plurality of lower bridge transistors, and calculate the voltage difference between the first terminal and the second terminal of any one of the plurality of lower bridge transistors; The control circuit determines whether a reverse current flows through the motor according to a voltage difference between a first terminal and a second terminal of any one of the plurality of lower bridge transistors received from the reverse current detection circuit.

11. The motor driving circuit with reverse current detection mechanism according to claim 2, characterized in that: The reverse current detection circuit comprises an operational amplifier, a first input terminal of the operational amplifier is coupled to a voltage difference between an anode and a cathode of a body diode of any one of the plurality of lower bridge transistors, a second input terminal of the operational amplifier is coupled to a reference voltage, and an output terminal of the operational amplifier is coupled to an input terminal of the control circuit; The control circuit determines whether a reverse current flows through the motor according to an operational amplification signal received from the operational amplifier.

12. The motor driving circuit with reverse current detection mechanism according to claim 1, characterized in that: The reverse current detection circuit comprises an operational amplifier, a first input terminal of the operational amplifier is coupled to the first terminal, the second terminal or the third terminal of the motor, a second input terminal of the operational amplifier is coupled to a reference voltage, and an output terminal of the operational amplifier is coupled to an input terminal of the control circuit; The control circuit determines whether a reverse current flows through the motor according to an operational amplification signal received from the operational amplifier.

13. The motor driving circuit with reverse current detection mechanism according to claim 1, characterized in that: The motor is a single-phase motor.

14. The motor driving circuit with reverse current detection mechanism according to claim 1, characterized in that: The motor is a three-phase motor.

15. The motor driving circuit with reverse current detection mechanism according to claim 1, characterized in that: The motor drive circuit with reverse current detection mechanism further comprises: A rotor position detection circuit is connected to the motor and the control circuit. The rotor position detection circuit is configured to detect the rotor position of the motor to output a rotor position detection signal. The control circuit controls the drive circuit according to the rotor position detection signal received from the rotor position detection circuit.

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