Reverse polarity protection motor control circuit and motor system
By using an NMOS transistor in conjunction with a bootstrap unit in the reverse polarity protection motor control circuit, the problems of circuit complexity and high power consumption in high-power environments are solved, achieving low-power and low-cost motor control.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI GONGCHENG SEMICON TECH CO LTD
- Filing Date
- 2025-03-25
- Publication Date
- 2026-06-30
AI Technical Summary
Existing reverse polarity protection motor control circuits consume a lot of power when using PMOS transistors in high-power environments, and when using NMOS transistors, an additional bootstrap module is required, increasing circuit complexity, and communication interference and fault problems exist.
By using an NMOS transistor in conjunction with a bootstrap unit, the voltage is boosted through the bootstrap unit in subsequent circuits, avoiding the introduction of an additional bootstrap circuit in the reverse connection protection module. The bootstrap unit provides a bootstrap signal to the NMOS transistor, simplifying the circuit design.
It reduces circuit power consumption and cost, simplifies circuit design, avoids communication interference and malfunctions, and improves circuit reliability.
Smart Images
Figure CN224438567U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of semiconductor circuit control, and in particular to a reverse-connection motor control circuit and motor system. Background Technology
[0002] A reverse polarity protection motor control circuit is used to protect the motor controller from damage caused by reverse power supply polarity. It ensures the motor operates normally when the power supply polarity is correct, preventing malfunctions and damage caused by reverse connection. Generally, a reverse polarity protection motor control circuit includes a detection unit and a control protection unit. The detection unit detects the power supply polarity and outputs a control signal to the control protection unit when the polarity is correct; the control protection unit then outputs power to subsequent circuits based on the control signal. However, current control protection units that directly use PMOS transistors are not suitable for high-power environments; while those that directly use NMOS transistors are limited by their internal structure and require voltage settings, necessitating a separate reference ground or an additional bootstrap module in the control protection unit. Both of these methods increase the complexity of the circuit design and introduce potential communication interference and malfunctions.
[0003] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content
[0004] In view of the shortcomings of the prior art described above, the purpose of this utility model is to provide a reverse connection motor control circuit and motor system to solve the problems of high power consumption, complex circuit design, and potential communication and failure issues in the prior art.
[0005] To achieve the above and other related objectives, this utility model provides a reverse connection protection motor control circuit, including: a reverse connection protection module and a motor control module;
[0006] The two input terminals of the reverse connection protection module are respectively used as two ports to connect to the power supply under test. The output terminal outputs a working signal, and the control terminal receives the bootstrap signal output by the motor control module. Based on the polarity of the power supply under test, the working signal output by the reverse connection protection module is turned on or off.
[0007] The motor control module includes N phase control units and N bootstrap units; each phase control unit is configured in a one-to-one correspondence with its corresponding bootstrap unit; each phase control unit includes a high-side control section and a low-side control section; the operating signal is sequentially connected to a reference ground via the high-side control section and the low-side control section, and the control terminals of the high-side control section and the low-side control section respectively receive different control signals; the node connecting the high-side control section and the low-side control section serves as an output node, and the output node serves as the output terminal of the corresponding phase control unit; the first terminal of the bootstrap unit is connected to the bootstrap voltage, and the second terminal is connected to the output node of the phase control unit and the reverse connection protection module to output the bootstrap signal. Optionally, the bootstrap unit includes a first diode, a second diode, a first capacitor, and a driving component;
[0008] The anode of the first diode is connected to the bootstrap voltage, and the cathode is connected to the anode of the second diode and the first plate of the first capacitor, respectively. The first plate of the first capacitor is also connected to the input terminal of the driving component, and the second plate is connected to the output node. The output terminal of the driving component is connected to the control terminal of the high-side control unit. The cathode of the second diode is connected to the control terminal of the reverse connection protection module.
[0009] Optionally, the reverse connection protection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a third diode, a fourth diode, a second capacitor, a first NMOS transistor, and a transistor; the source of the first NMOS transistor and the first terminal of the first resistor respectively serve as two ports of the power supply to be tested; the second terminal of the first resistor is connected to the base of the transistor; the emitter of the transistor is connected to the source of the first NMOS transistor via the third diode, and the collector is connected to the gate of the first NMOS transistor; the second resistor is disposed between the emitter and the base of the transistor; the third resistor, the fourth diode, and the second capacitor are connected in parallel and disposed between the source and the gate of the first NMOS transistor; the drain of the first NMOS transistor outputs the working signal, and the gate is connected to the first terminal of the fourth resistor; the second terminal of the fourth resistor serves as the control terminal of the reverse connection protection module.
[0010] Optionally, the high-side control unit includes a second NMOS transistor; the low-side control unit includes a third NMOS transistor; the drain of the second NMOS transistor is connected to the operating signal, the gate is connected to the high-side control signal, and the source is connected to the output node; the drain of the NMOS transistor is connected to the output node, the gate is connected to the low-side control signal, and the drain is connected to reference ground.
[0011] Optionally, the high-side control unit further includes a fifth resistor and a sixth resistor; the first end of the fifth resistor receives the high-side control signal, and the second end is connected to the gate of the second NMOS transistor; the first end of the sixth resistor is connected to the gate of the second NMOS transistor, and the second end is connected to the output node.
[0012] Optionally, the low-side control unit further includes a seventh resistor and an eighth resistor; the first end of the seventh resistor receives the low-side control signal, and the second end is connected to the gate of the third NMOS transistor; the first end of the eighth resistor is connected to the gate of the third NMOS transistor, and the second end is connected to reference ground.
[0013] Optionally, N is set to 3.
[0014] To achieve the above and other related objectives, this utility model provides a motor system, including: a load motor, a control circuit, and the aforementioned reverse connection protection motor control circuit;
[0015] The output terminal of the control circuit is connected to the control terminal of each of the high-side control units and the control terminal of each of the low-side control units, respectively, to provide the high-side control signal and the low-side control signal; wherein, in each phase control unit output by the control circuit, a pair of high-side control signals and low-side control signals are complementary.
[0016] The reverse connection protection motor control circuit receives the power supply to be tested and the control signal output by the control circuit, and outputs the rectified electrical signal to the load motor.
[0017] Optionally, N is set to 3, and the phase difference between each of the high-side control signals is set to 120°.
[0018] As described above, the reverse polarity protection motor control circuit and motor system of this utility model have the following beneficial effects:
[0019] This invention uses a bootstrap unit in the subsequent circuit to boost the voltage of the NMOS transistor in the reverse connection protection module, avoiding the introduction of an additional bootstrap circuit in the reverse connection protection module, which would cause circuit complexity or affect device performance due to multiple reference grounds. At the same time, this embodiment only uses a diode to move the bootstrap voltage of the subsequent circuit to the gate of the NMOS transistor. The circuit is simple and easy to manufacture, and has great application prospects. Moreover, it has lower power consumption and lower cost compared to using a PMOS transistor. Attached Figure Description
[0020] Figure 1 The diagram shown is a structural schematic of the first type of motor controller.
[0021] Figure 2 The diagram shown is a structural schematic of the second type of motor controller.
[0022] Figure 3 The diagram shown is a structural schematic of the third type of motor controller.
[0023] Figure 4 The diagram shown is a structural schematic of the motor system of this utility model.
[0024] Component designation explanation
[0025] 1 motor controller 11 Reverse connection protection module 11’ Reverse connection protection module 11” Reverse connection protection module 12 Motor control module 13 motor 2 motor system 21 Reverse polarity protection motor control circuit 211 Reverse connection protection module 212 Motor control module 2121 Self-bootstrapping unit 2122 Phase control unit 2122a High-side control unit 2122b Low-side control unit 22 Load motor Detailed Implementation
[0026] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model.
[0027] Please see Figures 1-4 It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of this utility model. Therefore, the drawings only show the components related to this utility model and are not drawn according to the actual number, shape and size of the components. In actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.
[0028] Comparative Example
[0029] Figure 1 A motor controller 1 is provided, including a reverse connection protection module 11, a motor control module 12, and a motor 13; the reverse connection protection module 11 is disposed between the motor control module 12 and the battery power supply, and is provided when the polarity of the battery power supply is correctly connected (e.g., ...). Figure 1 When the battery polarity is reversed (the upper side is the positive battery voltage BAT, and the lower side is the negative battery reference ground GND), the power supply voltage is provided to the motor control module 12. When the battery polarity is reversed (the upper side is not the positive battery voltage BAT, and the lower side is not the reference ground GND), the power supply voltage to the motor control module 12 is prohibited to avoid burning out the motor control module 12. The rectified current is provided to the motor 13 through the motor control module 12.
[0030] Figure 1The reverse connection protection module 11 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor, a first diode D1, a first transistor Q1, and a second transistor Q2. The first transistor Q1 is a PMOS transistor; the drain of the PMOS transistor is connected to the first terminal (power supply terminal BAT) of the battery power supply, and the gate is connected to the collector of the second transistor Q2 (a transistor) via the third resistor R3. The source outputs the supply voltage VM. The first resistor R1 is positioned between the drain and gate of the first transistor Q1. The first terminal of the second resistor R2 is connected to the first terminal of the battery power supply, and the second terminal is connected to the base of the second transistor Q2. The cathode of the first diode D1 is connected to the base of the second transistor Q2, and the anode is connected to the emitter of the second transistor Q2. The fourth resistor R4 is connected between the base and emitter of the second transistor Q2. The emitter of the second transistor Q2 is also connected to a reference ground.
[0031] Figure 1The motor control module 12 includes a second diode D2, a third diode D3, a fourth diode D4, a third transistor Q3, a fourth transistor Q4, a fifth transistor Q5, a sixth transistor Q6, a seventh transistor Q7, an eighth transistor Q8, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, and a sixteenth resistor R16. Specifically, the first terminal of the third transistor Q3 is connected to the supply voltage VM, and the second terminal is connected to the first terminal of the sixth transistor Q6; the first terminal of the sixth transistor Q6 also outputs the first phase signal U, and the second terminal is connected to the reference ground; the first terminal of the fourth transistor Q4 is connected to the supply voltage VM, and the second terminal is connected to the first terminal of the seventh transistor Q7; the first terminal of the seventh transistor Q7 also outputs the second phase signal V, and the second terminal is connected to the reference ground; the first terminal of the fifth transistor Q5 is connected to the supply voltage VM, and the second terminal is connected to the first terminal of the eighth transistor Q8; the first terminal of the eighth transistor Q8 also outputs the third phase signal W, and the second terminal is connected to the reference ground. In this configuration, the anodes of the second diode D2, the third diode D3, and the fourth diode D4 are all connected to the boost voltage VCC_Drv, and their cathodes are connected to the upper plates of the first capacitor C1, the second capacitor C2, and the third capacitor C3, respectively. The lower plates of the first capacitor C1, the second capacitor C2, and the third capacitor C3 are connected to the sources of the third transistor Q3, the fourth transistor Q4, and the fifth transistor Q5, respectively. The first terminal of the fifth resistor R5 receives the first high-order control signal Drv_UH, and the second terminal is connected to the gate of the third transistor Q3. The first terminal of the sixth resistor R6 receives the second high-order control signal Drv_VH, and the second terminal is connected to the gate of the fourth transistor Q4. The first terminal of the seventh resistor R7 receives the third high-order control signal Drv_WH, and the second terminal is connected to the gate of the fourth transistor Q4. The fifth resistor is connected to the gate of transistor Q5; the eighth resistor R8 is connected to the gate and source of the third transistor Q3; the ninth resistor R8 is connected to the gate and source of the fourth transistor Q4; the tenth resistor R10 is connected to the gate and source of the fifth transistor Q5; one end of the eleventh resistor R11 is connected to the first low-order control signal Drv_UL, and the second end is connected to the gate of the sixth transistor Q6; one end of the twelfth resistor R12 is connected to the second low-order control signal Drv_VL, and the second end is connected to the gate of the seventh transistor Q7; one end of the thirteenth resistor R13 is connected to the third low-order control signal Drv_WL, and the second end is connected to the gate of the eighth transistor Q8; the fourteenth resistor R14 is connected to the source and gate of the sixth transistor Q6; the fifteenth resistor R15 is connected to the source and gate of the seventh transistor Q7; and the sixteenth resistor R16 is connected to the source and gate of the eighth transistor Q8.
[0032] Figure 1The motor 13 receives the first phase signal V, the second phase signal U, and the third phase signal W, and performs its work based on each phase signal.
[0033] in, Figure 1 The first transistor Q1 of the motor controller 1 is connected to the power supply terminal BAT. By controlling the second transistor Q2, the first transistor Q1 is controlled to turn on and off, thereby ensuring that the first transistor Q1 is disconnected when the polarity of the battery power supply is reversed, and the subsequent motor control module 12 loses the power supply voltage VM.
[0034] but Figure 1 The PMOS transistor plays a crucial role in reverse polarity protection. However, in high-power applications, the PMOS transistor has both high power consumption and high cost. Therefore, this comparative example provides a reverse polarity protection setting using an NMOS transistor, such as... Figure 2 As shown, the motor control module 12 and the motor 13 have not been changed, only the reverse connection protection module 11' has been adapted.
[0035] like Figure 2 The reverse connection protection module 11' includes: a seventeenth resistor R17, an eighteenth resistor R18, and a ninth transistor Q9. The ninth transistor Q9 is an NMOS transistor; the drain of the NMOS transistor is connected to the first reference ground GND1, the source is connected to the second reference ground GND2 (the second reference ground also serves as the reference ground for the motor control module 12), and the gate is connected to the power supply terminal BAT via the seventeenth resistor R17; the eighteenth resistor R18 is connected between the gate and source of the NMOS transistor. To ensure smooth turn-on and turn-off of the NMOS transistor, the first reference ground GND1 and the second reference ground GND2 are not the same. This configuration reduces the integrity of the ground line, and in practical use, isolation from external communication must also be considered.
[0036] Based on this, this comparative example also provides another setting for reverse connection protection of the NMOS transistor. This is achieved by adding a bootstrap unit to the reverse connection protection module to bootstrap the NMOS transistor, such as... Figure 3 As shown.
[0037] Figure 3The motor control module 12 and motor 13 of the motor controller 1 remain unchanged; only the reverse connection protection module 11” has been adapted. The reverse connection protection module 11” includes a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a fifth diode D5, a tenth transistor Q10, an eleventh transistor Q11, and a bootstrap unit 111. The tenth transistor Q10 is an NMOS transistor, with its source connected to the power supply terminal BAT, its drain outputting the supply voltage VM, and its gate connected to both the collector of the eleventh transistor Q11 and the voltage signal output by the bootstrap circuit 111. The nineteenth resistor R19 is connected between the gate and source of the tenth transistor. The emitter of the eleventh transistor Q11 is connected to the power supply terminal BAT via the fifth diode D5, and its base is connected to the reference ground via the twenty-first resistor R21. The twentieth resistor R20 is connected between the base and emitter of the eleventh transistor. The input of the bootstrap unit 111 is connected to the power supply terminal BAT, and the bootstrap unit 111 is also connected to the reference ground. In this method, an additional bootstrap unit 111 is used to charge the NMOS transistor. However, the addition of the bootstrap unit 111 increases the complexity of the circuit and the cost of the product.
[0038] To solve the above problems, this embodiment provides a reverse-connection motor control circuit 21, such as... Figure 4 As shown, it includes: reverse connection protection module 211 and motor control module 212.
[0039] like Figure 4 As shown, the two input terminals of the reverse connection protection module 211 serve as the two ports for connecting to the power supply under test (Battery). The output terminal outputs a working signal VM, and the control terminal receives the bootstrap signal output by the motor control module 212. Based on the polarity of the power supply under test (Battery), the working signal VM output by the reverse connection protection module 211 is turned on or off. In this embodiment, when the upper side of the power supply under test is positive and the lower side is negative, the circuit conducts normally, and the reverse connection protection module 211 outputs the working signal VM. When the lower side of the power supply under test is positive and the upper side is negative, the circuit is disconnected, and the reverse connection protection module 211 does not output the working signal VM.
[0040] Specifically, in this embodiment, the reverse connection protection module 211 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a third diode D3, a fourth diode D4, a second capacitor C2, a first NMOS transistor N1, and a transistor Q1. The source of the first NMOS transistor N1 and the first terminal of the first resistor R1 serve as two ports of the power supply to be tested (the source of the first NMOS transistor N1 is connected to the positive terminal of the power supply to be tested, and the base of the first resistor R1 is connected to the reference ground of the power supply to be tested). The second terminal of the first resistor R1 is connected to the base of the transistor Q1. The emitter of the transistor Q1 is connected to the source of the first NMOS transistor N1 via the third diode D3, and the collector is connected to the first NMOS transistor C2. The first NMOS transistor N1 has a gate; a second resistor R2 is placed between the emitter and base of transistor Q1; a third resistor R3, a fourth diode D4, and a second capacitor C2 are connected in parallel between the source and gate of the first NMOS transistor N1; the third resistor R3 provides a static voltage to prevent interference-induced malfunction; the fourth diode D4 prevents the gate-source voltage from exceeding the withstand voltage of the first NMOS transistor N1; the second capacitor C2 is used for anti-interference to prevent interference-induced malfunction; the drain of the first NMOS transistor N1 outputs the working signal VM, and its gate is connected to the first terminal of the fourth resistor R4; the second terminal of the fourth resistor R4 serves as the control terminal of the reverse connection protection module 211, receiving subsequent bootstrap signals and outputting them to the gate of the first NMOS transistor N1. The first resistor R1, the second resistor R2, transistor Q1, and the third diode D3 are all used to limit the gate-source voltage of the first NMOS transistor N1, keeping it below the turn-on voltage. In this embodiment, the reverse connection protection operation is performed by an NMOS transistor in conjunction with a transistor. The bootstrap signal of the NMOS transistor comes from the subsequent motor control module 212, and there is no need to set up an additional bootstrap unit in the reverse connection protection module 211.
[0041] It should be noted that the specific structure of the actual reverse connection protection module 211 is not limited to this embodiment. In fact, as long as the NMOS transistor in the reverse connection protection module 211 is charged by the subsequent motor control module 212 to perform the reverse connection protection setting, it is within the protection scope of this embodiment.
[0042] like Figure 4As shown, the motor control module 212 includes N phase control units 2122 and N bootstrap units 2121; each phase control unit 2122 is configured in a one-to-one correspondence with its corresponding bootstrap unit 2121; each phase control unit 2122 includes a high-side control section 2122a and a low-side control section 2122b; the working signal VM is connected to the reference ground GND sequentially through the high-side control section 2122a and the low-side control section 2122b, and the control terminals of the high-side control section 2122a and the low-side control section 2122b respectively receive different control signals; the node connecting the high-side control section 2122a and the low-side control section 2122b serves as an output node, and the output node serves as the output terminal of the corresponding phase control unit; the first terminal of the bootstrap unit 2121 is connected to the bootstrap voltage VCC_DRV, and the second terminal is connected to the phase control unit and the reverse connection protection module 211 respectively to output the bootstrap signal.
[0043] Specifically, the bootstrap unit 2121 includes a first diode D1, a second diode D2, a first capacitor C1, and a driving component (not shown in the figure). The anode of the first diode D1 is connected to the bootstrap voltage VCC_DRV, and the cathode is connected to the anode of the second diode D2 and the first plate of the first capacitor C1, respectively. The first plate of the first capacitor is also connected to the input terminal of the driving component, and the second plate of the first capacitor C1 is connected to the output node. The output terminal of the driving component is connected to the control terminal of the high-side control unit. The cathode of the second diode D2 is connected to the control terminal of the reverse connection protection module 211 to output a bootstrap signal. The bootstrap unit 2121, located in the motor control module 212, simultaneously provides bootstrap voltage to both the phase control unit 2122 and the reverse connection protection module 211. In this embodiment, the low-side NMOS transistor is turned on, the high-side NMOS transistor is turned off, and the first capacitor C1 is charged. When the low-side NMOS transistor is turned off, the high-side NMOS transistor is turned on, the first capacitor C1 discharges, and the driving component converts the voltage, thereby boosting the gate drive voltage of the first NMOS transistor to VM+VCC_Drv, ensuring smooth driving. Meanwhile, when reversed, transistor Q1 is turned on, and the gate voltage of the first NMOS transistor N1 is clamped to VQ1+VD3 by transistor Q1. The first NMOS transistor N1 is turned off, and the output of the working signal VM is stopped.
[0044] It should be noted that the configuration of the bootstrap unit 2121 is not limited to this embodiment. In some configurations, resistors, capacitors, etc., can be added as needed. In fact, as long as the bootstrap operation can be guaranteed by charging and discharging through the bootstrap voltage VCC_DRV, it is within the protection scope of this embodiment. In this embodiment, voltage bootstrap can be achieved by only setting the second diode D2, which greatly reduces the complexity of the circuit and improves the integration of the design.
[0045] Specifically, the high-side control unit 2122a includes a second NMOS transistor N2; the low-side control unit 2122b includes a third NMOS transistor N3; the drain of the second NMOS transistor N2 is connected to the working signal VM, the gate is connected to the high-side control signal, and the source is connected to the output node; the drain of the third NMOS transistor N3 is connected to the output node, the gate is connected to the low-side control signal, and the drain is connected to the reference ground GND. In this embodiment, the high-side control signals received by the high-side control unit 2122a and the low-side control unit 2122b within the same phase control unit 2122 are complementary to the low-side control signals, meaning that when the high-side of the phase control unit 2122 is turned on, the low-side is turned off, and there is no simultaneous conduction interference. Furthermore, in this embodiment, there is a certain phase difference between the multiple phase control units 2122.
[0046] As an example, the high-side control unit 2122a also includes a fifth resistor R5 and a sixth resistor R6; the first end of the fifth resistor R5 receives the high-side control signal, and the second end is connected to the gate of the second NMOS transistor N2; the first end of the sixth resistor R6 is connected to the gate of the second NMOS transistor N2, and the second end is connected to the output node.
[0047] As an example, the low-side control unit 2122b also includes a seventh resistor R7 and an eighth resistor R8; the first end of the seventh resistor R7 receives the low-side control signal, and the second end is connected to the gate of the third NMOS transistor N3; the first end of the eighth resistor R8 is connected to the gate of the third NMOS transistor N3, and the second end is connected to the reference ground.
[0048] In this embodiment, before the phase control unit 2122 is driven, a bootstrap operation is required via the first diode D1. The high-side control unit 2122a and the low-side control unit 2122b are alternately turned on, thereby raising the voltage across the first capacitor C1 in the bootstrap unit 2121 to VCC_Drv. In this embodiment, when the high-side control unit 2122a is turned on, the negative voltage of the first capacitor C1 is VM, while the positive voltage is raised to VM+VCC_Drv (the bootstrap signal is provided to the phase control unit 2122 and the reverse connection protection module 211, respectively).
[0049] In this embodiment, N is set to 3, which means there are three phase control units 2122. The three-phase control units 2122 provide the first phase signal U, the second phase signal W, and the third phase signal V respectively and output them from the output port of the reverse connection motor control circuit 21.
[0050] It should be noted that, in this embodiment, by setting N equal to 3, it is ensured that when any one phase bootstrap unit 2121 is charging (low-side control unit 2122b is on, high-side control unit 2122a is off), the other two phase bootstrap units 2121 have already finished charging and are bootstrapping the gate of the first NMOS transistor. The charging cycle of the bootstrap unit depends on the resistance of the charging circuit and the capacitance of the first capacitor C1. Therefore, in this embodiment, at least the bootstrap voltage duration required to match the charging of the first NMOS transistor N1 must be considered to set the number of phase control units 2122.
[0051] It should be further explained that, in this embodiment, the bootstrap voltage required by the first NMOS transistor and the NMOS in the high-side control unit 2122a, the capacitance of the first capacitor C1, and the charging frequency and bootstrap time between each first capacitor C1 are set to avoid problems such as excessively fast or slow switching frequencies between the first capacitors C1, which would lead to excessively long charging or discharging times. Meanwhile, the frequency of the three-phase control unit is relatively fixed, including the maximum duty cycle and the minimum duty cycle. The capacitance value of the first capacitor C1 and the internal resistance damage during the discharge process are designed accordingly based on the frequency, maximum duty cycle, and minimum duty cycle.
[0052] This embodiment also provides a motor system 2, including: a load motor 22, a control circuit (not shown in the figure), and the above-mentioned reverse connection protection motor control circuit 21.
[0053] The output terminals of the control circuit are connected to the control terminals of each high-side control unit and each low-side control unit, respectively, providing high-side control signals and low-side control signals. In each phase control unit 2122 output by the control circuit, the pair of high-side and low-side control signals are complementary. For the same phase phase control unit 2122, by setting complementary high-side and low-side control signals, when the high-side control signal is high, the corresponding low-side control signal is low, and vice versa. This complementary relationship ensures that the high-side and low-side MOSFETs of the same phase will not be simultaneously turned on at any time, thereby preventing shoot-through between the upper and lower bridge arms and protecting the circuit from damage.
[0054] The reverse polarity protection motor control circuit 21 receives the power supply to be detected and the control signals (multiple high-side control signals and multiple low-side control signals) output by the control circuit, and outputs the rectified electrical signal to the load motor 22. Specifically, N is set to 3, and the phase difference between each high-side control signal is set to 120°. In a three-phase drive circuit, the control signals of the three phases usually have a certain phase difference to achieve effective control of the three-phase motor. In the six-step commutation control, the high-side and low-side control signals of each phase are switched according to a specific timing sequence to achieve six-step operation of the motor. The timing sequence of each step needs to be precisely controlled to ensure that the motor rotates in the expected direction and speed. In this embodiment, the capacitance value of the bootstrap unit needs to be set based on the switching timing sequence and the charging and discharging time and cycle. The specific parameters to be considered can be set as described above.
[0055] In summary, this invention provides a reverse-connection motor control circuit and a motor system. The reverse-connection motor control circuit includes a reverse-connection protection module and a motor control module. The two input terminals of the reverse-connection protection module serve as two ports for connecting to the power supply under test, and the output terminal outputs a working signal. The control terminal receives the bootstrap signal output by the motor control module. The motor control module includes N phase control units and N bootstrap units. Each phase control unit includes a high-side control section and a low-side control section. The working signal is sequentially connected to a reference ground via the high-side control section and the low-side control section. The node connecting the high-side control section and the low-side control section serves as an output node. The first terminal of each bootstrap unit is connected to a bootstrap voltage, and the second terminal is connected to the output node and the reverse-connection protection module to output a bootstrap signal. This invention boosts the voltage at the control terminal of the reverse-connection protection module through the bootstrap unit in a subsequent circuit, avoiding the introduction of an additional bootstrap circuit in the reverse-connection protection module. Therefore, this invention effectively overcomes the various shortcomings of the prior art and has high industrial applicability.
[0056] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.
Claims
1. A reverse-connection motor control circuit, characterized in that, The reverse connection protection motor control circuit includes a reverse connection protection module and a motor control module; The two input terminals of the reverse connection protection module are respectively used as two ports to connect to the power supply under test. The output terminal outputs a working signal, and the control terminal receives the bootstrap signal output by the motor control module. Based on the polarity of the power supply under test, the working signal output by the reverse connection protection module is turned on or off. The motor control module includes N phase control units and N bootstrap units; each phase control unit is configured in a one-to-one correspondence with its respective bootstrap unit; each phase control unit includes a high-side control section and a low-side control section; the operating signal is sequentially connected to a reference ground via the high-side control section and the low-side control section, and the control terminals of the high-side control section and the low-side control section respectively receive different control signals; the node connecting the high-side control section and the low-side control section serves as an output node, and the output node serves as the output terminal of the corresponding phase control unit; the first terminal of the bootstrap unit is connected to the bootstrap voltage, and the second terminal is connected to the phase control unit and the reverse connection protection module respectively to output the bootstrap signal.
2. The reverse polarity protection motor control circuit according to claim 1, characterized in that: The bootstrap unit includes a first diode, a second diode, a first capacitor, and a driving component; The anode of the first diode is connected to the bootstrap voltage, and the cathode is connected to the anode of the second diode and the first plate of the first capacitor, respectively. The first plate of the first capacitor is also connected to the input terminal of the driving component, and the second plate is connected to the output node; The output end of the drive component is connected to the control end of the high-side control unit; The cathode of the second diode is connected to the control terminal of the reverse connection protection module.
3. The reverse polarity protection motor control circuit according to claim 1, characterized in that: The reverse connection protection module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a third diode, a fourth diode, a second capacitor, a first NMOS transistor, and a transistor. The source of the first NMOS transistor and the first terminal of the first resistor serve as the two ports of the power supply to be detected. The second end of the first resistor is connected to the base of the transistor; The emitter of the transistor is connected to the source of the first NMOS transistor via the third diode, and the collector is connected to the gate of the first NMOS transistor; the second resistor is disposed between the emitter and the base of the transistor. The third resistor, the fourth diode, and the second capacitor are connected in parallel and disposed between the source and gate of the first NMOS transistor; The working signal is output from the drain of the first NMOS transistor, and the gate is connected to the first terminal of the fourth resistor; The second end of the fourth resistor serves as the control terminal of the reverse connection protection module.
4. The reverse polarity protection motor control circuit according to claim 1, characterized in that: The high-side control unit includes a second NMOS transistor; the low-side control unit includes a third NMOS transistor. The drain of the second NMOS transistor is connected to the working signal, the gate is connected to the high-side control signal, and the source is connected to the output node; The drain of the third NMOS transistor is connected to the output node, the gate is connected to the low-side control signal, and the drain is connected to the reference ground.
5. The reverse polarity protection motor control circuit according to claim 4, characterized in that: The high-side control unit also includes a fifth resistor and a sixth resistor; The first end of the fifth resistor receives the high-side control signal, and the second end is connected to the gate of the second NMOS transistor; The first end of the sixth resistor is connected to the gate of the second NMOS transistor, and the second end is connected to the output node.
6. The reverse polarity protection motor control circuit according to claim 4, characterized in that: The low-side control unit also includes a seventh resistor and an eighth resistor; The first end of the seventh resistor receives the low-side control signal, and the second end is connected to the gate of the third NMOS transistor; The first end of the eighth resistor is connected to the gate of the third NMOS transistor, and the second end is connected to reference ground.
7. The reverse polarity protection motor control circuit according to claim 1, characterized in that: N is set to 3.
8. A motor system comprising a load motor, a control circuit, and a reverse connection protection motor control circuit as described in any one of claims 1 to 7, characterized in that: The output terminal of the control circuit is connected to the control terminal of each of the high-side control units and the control terminal of each of the low-side control units, respectively, to provide the high-side control signal and the low-side control signal; wherein, in each phase control unit output by the control circuit, a pair of high-side control signals and low-side control signals are complementary. The reverse connection protection motor control circuit receives the power supply to be tested and the control signal output by the control circuit, and outputs the rectified electrical signal to the load motor.
9. The motor system according to claim 8, characterized in that: N is set to 3, and the phase difference between each of the high-side control signals is set to 120°.