Bootstrap integrated circuit for direct current brushless motor

Abstract

The utility model provides a bootstrap integrated circuit for a direct current brushless motor. The bootstrap integrated circuit comprises a circuit board, a single-chip microcomputer MCU and an external circuit. Wherein a boost diode is arranged in the single-chip microcomputer MCU, and the outside of the single-chip microcomputer MCU is connected with the outside through a pin; the external circuit is provided with a charging capacitor which is connected with the outside through a pin for voltage transmission. According to the bootstrap integrated circuit for the direct current brushless motor provided by the utility model, the boost diode is integrated into the MCU, so that an external bootstrap circuit is simplified, the occupied space of electronic elements on a circuit board is reduced, circuit connection is realized only through pins, the space utilization rate of a PCB (Printed Circuit Board) is improved, the design is more convenient, and the product is more reliable.

Description

Technical Field

[0001] The utility model relates to a bootstrap integrated circuit for a DC brushless motor. Background Art

[0002] In a traditional DC brushless motor (BLDC), a bootstrap circuit, also called a boost circuit, uses electronic components such as a boost diode and a bootstrap boost capacitor to superimpose the capacitor discharge voltage and the power supply voltage, thereby increasing the voltage. In some circuits, the increased voltage can reach several times the power supply voltage. In a traditional DC brushless motor (BLDC), the motor drives the stator coil through a three-phase H-bridge circuit ( Figure 1 as shown), the midpoint lead (electrical network number U) of the upper transistor Q1-MOS and the lower transistor Q4-MOS controls the U phase; the midpoint lead (electrical network number V) of the upper transistor Q2-MOS and the lower transistor Q5-MOS controls the V phase; the midpoint lead (electrical network number W) of the upper transistor Q3-MOS and the lower transistor Q6-MOS controls the W phase; and then through the motor drive bootstrap circuit ( Figure 2 as shown), the electrical network number VCC of the circuit is the power supply voltage of the bootstrap circuit; the electrical network numbers VBU, VBV, and VBW are the high-side floating absolute voltages of the U phase, V phase, and W phase respectively; the electrical network numbers U, V, and W are the high-side floating offset voltages (phase voltages of U, V, and W) of the U phase, V phase, and W phase respectively. The circuit consists of R1, D1, D2, D3, C1, C2, and C3, which provide gate drive voltages for the high-side MOS of the U phase, V phase, and W phase respectively. The bootstrap circuit R1, D1, C1 constitutes the gate drive voltage of the high-side MOS-Q1 of the U phase; the bootstrap circuit R1, D2, C2 constitutes the gate drive voltage of the high-side MOS-Q2 of the V phase; the bootstrap circuit R1, D3, C3 constitutes the gate drive voltage of the high-side MOS-Q3 of the W phase.

[0003] Thus, it is necessary to set three input circuits with different phases around the microcontroller MCU on the integrated circuit. For the bootstrap circuit on the pin side of the microcontroller MCU, due to the highly integrated structure of the microcontroller itself, the distance between its pins is very small. Once a complex circuit is arranged, it is necessary to borrow the space on the circuit board, which affects the circuit layout. At the same time, because the space is occupied, it will lead to the risk of SMT soldering, affecting the yield of the entire circuit board. Summary of the Utility Model

[0004] The utility model aims to provide a bootstrap integrated circuit for a DC brushless motor. By integrating the boost diode into the MCU, the peripheral circuit on the circuit board is simplified, thereby reducing the component layout space on the circuit board, achieving an integrated circuit layout, and improving the usable space of the circuit.

[0005] To solve the above problems, a bootstrap integrated circuit for a DC brushless motor provided by the utility model adopts the following technical solutions:

[0006] A bootstrap integrated circuit for a DC brushless motor, comprising a circuit board, a single-chip microcomputer MCU and an external circuit; wherein a boost diode is arranged inside the single-chip microcomputer MCU and is connected outward through pins; the external circuit is provided with a charging capacitor, which is connected to the outside through pins for voltage transmission.

[0007] Three boost diodes are provided, which are respectively connected to the three-phase H-bridge circuit in the brushless motor, and are set as the U-phase circuit, the V-phase circuit and the W-phase circuit. The boost diodes are also correspondingly set as the U-phase diode, the V-phase diode and the W-phase diode. Each phase has two pins connected outward to the three-phase H-bridge circuit of the motor.

[0008] Furthermore, the charging capacitor corresponds to the boost diode, and is also provided with a U-phase charging capacitor, a V-phase charging capacitor and a W-phase charging capacitor.

[0009] Furthermore, a U-phase input pin and a U-phase output pin are arranged on the U-phase diode; the U-phase input pin is connected outward to the U-phase circuit of the three-phase H-bridge circuit to receive the U-phase voltage; the U-phase output pin extends outward and is connected to an external electronic component, and a U-phase charging capacitor is connected between the two pins.

[0010] Furthermore, a V-phase input pin and a V-phase output pin are arranged on the V-phase diode; the V-phase input pin is connected outward to the V-phase circuit of the three-phase H-bridge circuit to receive the V-phase voltage; the V-phase output pin extends outward and is connected to an external electronic component, and a V-phase charging capacitor is connected between the two pins.

[0011] Furthermore, a W-phase input pin and a W-phase output pin are arranged on the W-phase diode; the W-phase input pin is connected outward to the W-phase circuit of the three-phase H-bridge circuit to receive the W-phase voltage; the W-phase output pin extends outward and is connected to an external electronic component, and a W-phase charging capacitor is connected between the two pins.

[0012] The beneficial effects of the present utility model are as follows: The bootstrap integrated circuit for a DC brushless motor provided by the present utility model simplifies the external bootstrap circuit by integrating the boost diode into the MCU, reduces the occupied space of electronic components on the circuit board, and realizes circuit connection only through pins, improving the space utilization rate of the printed circuit board (PCB) of the circuit board, making its design more convenient and the product more reliable. Description of the Drawings

[0013] Attached Figure 1 is a schematic diagram of the three-phase H-bridge circuit of the prior art of the present utility model.

[0014] Attached Figure 2Schematic diagram of the bootstrap circuit of the prior art of the present utility model.

[0015] Appendix Figure 3 Schematic diagram of the external circuit of the bootstrap integrated circuit of the present utility model.

[0016] Appendix Figure 4 Integration schematic diagram of the bootstrap integrated circuit of the present utility model.

[0017] Wherein: 1. U-phase circuit, 2. V-phase circuit, 3. W-phase circuit, 4. U-phase diode, 5. V-phase diode, 6. W-phase diode, 7. U-phase input pin, 8. U-phase output pin, 9. V-phase input pin, 10. V-phase output pin, 11. W-phase input pin, 12. W-phase output pin, 13. U-phase charging capacitor, 14. V-phase charging capacitor, 15. W-phase charging capacitor. Specific embodiments

[0018] In order to more clearly understand the technical solution provided by the present utility model, the following further describes the present utility model in conjunction with the accompanying drawings and specific embodiments.

[0019] As shown in the accompanying drawings, a bootstrap integrated circuit for a DC brushless motor provided by the present utility model includes a circuit board, a single-chip microcomputer MCU, and an external circuit; wherein a boost diode is provided inside the single-chip microcomputer MCU and is connected outward through pins; the external circuit is provided with a charging capacitor, which is connected to the outside through pins for voltage transmission;

[0020] Three boost diodes are provided, which are respectively connected to the three-phase H-bridge circuit in the brushless motor, and are set as the U-phase circuit 1, the V-phase circuit 2, and the W-phase circuit 3. The boost diodes are also correspondingly set as the U-phase diode 4, the V-phase diode 5, and the W-phase diode 6. Each phase has two pins connected to the three-phase H-bridge circuit of the motor outward.

[0021] Furthermore, the charging capacitors correspond to the boost diodes, and there are also a U-phase charging capacitor 13, a V-phase charging capacitor 14, and a W-phase charging capacitor 15.

[0022] Furthermore, a U-phase input pin 7 and a U-phase output pin 8 are provided on the U-phase diode 4; the U-phase input pin 7 is connected outward to the U-phase circuit 1 of the three-phase H-bridge circuit to receive the U-phase voltage; the U-phase output pin 8 extends outward and is connected to an external electronic component, and a U-phase charging capacitor 13 is connected between the two pins.

[0023] Further, a V-phase input pin 9 and a V-phase output pin 10 are provided on the V-phase diode 5; the V-phase input pin 9 is externally connected to the V-phase circuit 2 of the three-phase H-bridge circuit to receive the V-phase voltage; the V-phase output pin 10 extends outward and is connected to an external electronic component, and a V-phase charging capacitor 14 is connected between the two pins.

[0024] Further, a W-phase input pin 11 and a W-phase output pin 12 are provided on the W-phase diode 6; the W-phase input pin 11 is externally connected to the W-phase circuit 3 of the three-phase H-bridge circuit to receive the W-phase voltage; the W-phase output pin 12 extends outward and is connected to an external electronic component, and a W-phase charging capacitor 15 is connected between the two pins.

Claims

1. A bootstrap integrated circuit for a brushless DC motor, characterized in that: It includes a circuit board, a single-chip microcomputer MCU and an external circuit; wherein the single-chip microcomputer MCU is provided with a boost diode, which is connected to the outside through a pin; the external circuit is provided with a charging capacitor, which is connected to the outside through the pin to transmit voltage; The boost diodes are set to three, which are respectively connected to the three-phase H-bridge circuit in the brushless motor, and are set to U-phase circuit, V-phase circuit and W-phase circuit. The boost diodes are also correspondingly set to U-phase diode, V-phase diode and W-phase diode. The resistor of each phase is provided with two pins connected to the three-phase H-bridge circuit of the motor.

2. A bootstrap integrated circuit for a brushless DC motor according to claim 1, characterized in that: The charging capacitor corresponds to the boost diode, and is also provided with a U-phase charging capacitor, a V-phase charging capacitor and a W-phase charging capacitor.

3. A bootstrap integrated circuit for a brushless DC motor according to claim 2, characterized in that: The U-phase diode is provided with a U-phase input pin and a U-phase output pin; the U-phase input pin is externally connected to the U-phase circuit of the three-phase H-bridge circuit to receive the U-phase voltage; the U-phase output pin extends outward to connect to external electronic components, and a U-phase charging capacitor is connected between the two pins.

4. The bootstrap integrated circuit for a brushless DC motor according to claim 2, characterized in that: The V-phase diode is provided with a V-phase input pin and a V-phase output pin; the V-phase input pin is externally connected to the V-phase circuit of the three-phase H-bridge circuit to receive the V-phase voltage; the V-phase output pin extends outward to connect to external electronic components, and a V-phase charging capacitor is connected between the two pins.

5. The bootstrap integrated circuit for a brushless DC motor according to claim 2, characterized in that: The W-phase diode is provided with a W-phase input pin and a W-phase output pin; the W-phase input pin is externally connected to the W-phase circuit of the three-phase H-bridge circuit to receive the W-phase voltage; the W-phase output pin extends outward to connect to external electronic components, and a W-phase charging capacitor is connected between the two pins.

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