Three-phase current sampling circuit of integrated high-side MOS internal resistance power module

By integrating the three-phase current sampling circuit of the high-side MOS internal resistance power module, combined with LDO and high common-mode voltage differential op amp, the problems of high energy consumption and high failure rate in motor control are solved, and the current accuracy and Improved reliability avoids temperature drift and common mode interference.

CN119154756APending Publication Date: 2024-12-17ZHONGWEI YUXIN (CHONGQING) ELECTRONIC TECH CO LTD
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Patent Information

Application Number
CN202411289001.2
Authority / Receiving Office
CN · China
Patent Type
Applications(China)
Current Assignee / Owner
Filing Date
2024-09-14
Publication Date
2024-12-17

AI Technical Summary

Technical Problem

In the existing motor control, the three-phase current sampling method has problems such as high energy consumption, high failure rate and high cost. The traditional MOS internal resistance sampling method has problems such as temperature drift and common mode interference voltage heavy.

Method used

A three-phase current sampling circuit of integrated high-side MOS internal resistance power module is designed, using integrated high-side sampling op amp, LDO and power supply voltage sampling, integrated pre-driven and high-side MOS internal resistance sampling op amp, combined with NTC power module Circuit, which realizes a high common mode voltage differential op amp and resistive voltage divider network, and provides power supply to the MCU integrated LDO.

Benefits of technology

This circuit saves the external resistor required for traditional three-resistance sampling, reduces resistance loss and cost, simplifies the circuit, increases reliability, avoids ground interference, and detects motor windings short-circuits to ground, reducing failure rate.

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Abstract

The invention discloses a three-phase current sampling circuit of an integrated high-side MOS internal resistance power module. The circuit comprises an integrated high-side sampling operational amplifier + LDO + power supply voltage sampling micro-control unit U1 and integrated high-side MOS internal resistance sampling power transistors Q1 / Q2 / Q3. According to the circuit, three external sampling resistors required by three-resistor sampling are saved, the resistance loss is saved, the circuit is simplified, the cost is saved, and the reliability is improved. Compared with a traditional MOS internal resistance sampling circuit, the power module integrates pre-driving and high-side sampling high common-mode voltage differential operational amplification. The method has the advantages that grounding interference cannot be generated; and secondly, the ground short circuit of the motor winding can be detected. The MCU is integrated with the LDO and the high-side bus current sampling operational amplifier, so that the high-side bus current can be sampled, and the failure rate is reduced.
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Description

Technical Field

[0001] The present invention relates to the field of three-phase current sampling circuits, and in particular to a three-phase current sampling circuit with an integrated high-side MOS internal resistance power module. Background Art

[0002] At present, in order to collect the phase current of the motor in motor control, the common practices are: conventional 3-resistance sampling method. That is, 3 sampling resistors are connected in series in the lower bridge arm of the three-phase bridge arm circuit, and the three-phase current of the motor is obtained in the zero vector area of ​​SVPWM (space vector pulse width modulation). The collected current is then processed by the op amp and sent to the MCU for processing. This sampling method requires three sampling resistors, which has energy loss, increased failure rate and cost. Traditional MOS tube internal resistance sampling method. Compared with the traditional 3-resistance sampling, the external pre-drive + MOS internal resistance sampling directly samples the MOS internal resistance of the lower bridge arm of the 3-phase bridge arm as the sampling resistor. In this sampling method, the MOS internal resistance has temperature drift with the change of temperature. In order to ensure the current accuracy, temperature compensation is required. The op amp processing circuit requires an external parallel diode to prevent the high voltage of the phase voltage when the MOS tube is turned off. The op amp circuit cannot use a differential op amp structure, and the common mode interference voltage is heavy. Summary of the invention

[0003] In order to overcome the shortcomings and deficiencies of the prior art, a three-phase current sampling circuit of an integrated high-side MOS internal resistance power module is proposed.

[0004] The present invention provides a three-phase current sampling circuit of an integrated high-side MOS internal resistance power module, the circuit comprising: a micro control unit U1 integrated with a high-side sampling operational amplifier + LDO + power supply voltage sampling, and a power transistor Q1 / Q2 / Q3 integrated with a high-side MOS internal resistance sampling;

[0005] The microcontroller unit U1 is connected to the JP1 interface, the JP2 interface, the power transistors Q1, Q2, Q3, the resistors R1, R2, R3, R4, and the capacitors C1, C2, C3, C4 respectively; the motor M is connected to the power transistors Q1, Q2, Q3 for control;

[0006] The JP1 interface includes: Pin1 (VCC), a power supply pin, connected to the positive pole of the power supply; Pin2 (GND), a ground pin; Pin3 (VSP), connected to Pin6 of the micro control unit U1; Pin4 (FG), connected to Pin7 of the micro control unit U1; Pin5 (BRK), connected to Pin8 of the micro control unit U1;

[0007] The JP2 interface includes: 5V (Pin1), connected to Pin3 of the micro control unit U1, which is a 5V power input; GND (Pin2), connected to ground; SWDIO (Pin3), connected to Pin4 of the micro control unit U1; SWCLK (Pin4), connected to Pin5 of the micro control unit U1;

[0008] The micro control unit U1 includes: Pin1 (VCC), power input; Pin2 (GND), ground; Pin3 (5V), 5V power input; Pin4 (SWDIO), connected to JP2-3, used for debugging interface; Pin5 (SWCLK), connected to JP2-4, debugging clock interface; Pin6 (VSP), connected to JP1-3; Pin7 (FG), connected to JP1-4; Pin8 (BRK), connected to JP1-5; Pin9 (I / O): connected to R4 resistor and grounding capacitor; Pin10 (PWM2), connected to Pin3 of Q3; Pin11 (AN2): connected to the inside of the micro control unit U1; Pin12 (PWM1), connected to Pin3 of Q2; Pin14 (PWM0), connected to Pin3 of Q1; Pin16 (VRI), connected to VCC.

[0009] Furthermore, the power transistors Q1, Q2, and Q3 are responsible for driving the motor; their main interfaces are: Pin1 (GND), grounding; Pin2 (IO), connected to the control pin; Pin3 (IN), connected to different PWM pins of the microcontroller unit U1; Pin4 (EN), enable pin; Pin5-8 (OUT&VCC), control the power supply and output of the motor;

[0010] The motor (M) is controlled by Q1, Q2, and Q3, and is connected to the motor ends through three output pins to realize the driving control of the motor.

[0011] Furthermore, the resistor R1 is located in the power line and is connected in series in the circuit for current limiting protection;

[0012] The resistors R2, R3, and R4 are distributed in different signal paths and are used for voltage division, filtering, or impedance matching;

[0013] The capacitors C1, C2, C3, and C4 are used for decoupling and filtering to ensure signal stability;

[0014] The JP1 interface, the JP2 interface and the micro control unit U1 are connected via signal lines to provide control and power supply.

[0015] Furthermore, the microcontroller unit U1 is connected to Q1, Q2, and Q3 via PWM signal lines to control these power switches and thus drive the motor;

[0016] Resistors and capacitors are used for power supply decoupling and signal conditioning respectively.

[0017] Furthermore, the internal circuit of the power transistor Q1 / Q2 / Q3 is a power switch driving module, which includes logic control, a front driver, two MOSFET switches and corresponding input and output interfaces.

[0018] Furthermore, the microcontroller unit U1 integrates a high common-mode voltage sampling amplifier, samples the current of the high-side bus resistor R1, integrates an LDO to power the microcontroller, integrates a bus voltage divider circuit, and samples the voltage divider signal VBL with the ADC ANX channel inside the microcontroller.

[0019] Beneficial effects:

[0020] The present invention proposes a three-phase current sampling circuit of an integrated high-side MOS internal resistance power module, which integrates a pre-driver, a MOS, a high-side MOS internal resistance sampling operational amplifier, and an integrated NTC power module circuit. An MCU with an integrated high common-mode voltage operational amplifier, a resistor voltage divider network, and an integrated LDO. The circuit saves the three external sampling resistors required for traditional three-resistance sampling, saves resistor loss, simplifies the circuit, saves costs, and increases reliability. Compared with the traditional MOS internal resistance sampling circuit, the power module integrates a pre-driver and an integrated high-side sampling high common-mode voltage differential operational amplifier. Advantage 1: no ground interference will be generated; Advantage 2: short circuit of the motor winding to the ground can be detected. In the present invention, the MCU integrates an LDO and an integrated high-side bus current sampling operational amplifier, which can sample the high-side bus current and reduce the failure rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a circuit composition diagram of the present invention;

[0022] Figure 2 Internal circuit diagram of the microcontroller unit U1 of the present invention;

[0023] Figure 3 The internal circuit composition diagram of the power transistor Q1 / Q2 / Q3 of the present invention. DETAILED DESCRIPTION

[0024] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other. The present application is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0025] The technical solution adopted by the present invention is: including the integration of the operational amplifier in the micro-motor control M0 processor; the integration of the sampling power MOS structure in the micro-power module.

[0026] like Figure 1As shown, a three-phase current sampling circuit of a power module with integrated high-side MOS internal resistance includes: a microcontroller unit U1 with integrated high-side sampling operational amplifier + LDO + power supply voltage sampling, and power transistors Q1 / Q2 / Q3 with integrated high-side MOS internal resistance sampling;

[0027] The microcontroller unit U1 is connected to the JP1 interface, the JP2 interface, the power transistors Q1, Q2, Q3, the resistors R1, R2, R3, R4, and the capacitors C1, C2, C3, C4 respectively; the motor M is connected to the power transistors Q1, Q2, Q3 for control;

[0028] The JP1 interface includes: Pin1 (VCC), a power supply pin, connected to the positive pole of the power supply; Pin2 (GND), a ground pin; Pin3 (VSP), connected to Pin6 of the micro control unit U1; Pin4 (FG), connected to Pin7 of the micro control unit U1; Pin5 (BRK), connected to Pin8 of the micro control unit U1;

[0029] The JP2 interface includes: 5V (Pin1), connected to Pin3 of the micro control unit U1, which is a 5V power input; GND (Pin2), connected to ground; SWDIO (Pin3), connected to Pin4 of the micro control unit U1; SWCLK (Pin4), connected to Pin5 of the micro control unit U1;

[0030] The micro control unit U1 includes: Pin1 (VCC), power input; Pin2 (GND), ground; Pin3 (5V), 5V power input; Pin4 (SWDIO), connected to JP2-3, used for debugging interface; Pin5 (SWCLK), connected to JP2-4, debugging clock interface; Pin6 (VSP), connected to JP1-3; Pin7 (FG), connected to JP1-4; Pin8 (BRK), connected to JP1-5; Pin9 (I / O): connected to R4 resistor and grounding capacitor; Pin10 (PWM2), connected to Pin3 of Q3; Pin11 (AN2): connected to the inside of the micro control unit U1; Pin12 (PWM1), connected to Pin3 of Q2; Pin14 (PWM0), connected to Pin3 of Q1; Pin16 (VRI), connected to VCC.

[0031] The internal circuit composition of the microcontroller unit U1 is as follows: Figure 2 shown.

[0032] Power supply: The VCC pin on the upper left is the power input. 5VLDO: This is a low dropout linear regulator (LDO) responsible for converting a higher input voltage (which may be the voltage of VCC) into a 5V regulated power supply for use by the internal circuits.

[0033] Operational amplifier (OP): Input connected to IO pin, output connected to VRI and VBL. May be used for voltage sensing or feedback regulation.

[0034] Microcontroller (MCU): A Cortex-M0 32-bit microcontroller is used to process and generate control signals. The MCU communicates with external devices through I / O ports and mainly generates pulse width modulation (PWM) signals through PWM0, PWM1, and PWM3.

[0035] Resistor and ground connection: VBL is connected to ground through a resistor, which may be used for a voltage divider circuit or current sensing.

[0036] ANX pin: ANX is connected to one end of the Cortex-M0 MCU and is probably used to detect analog signals.

[0037] The device integrates power management, signal control and PWM output functions. The Cortex-M0 MCU controls external devices by generating PWM signals, while the operational amplifier is responsible for voltage detection and feedback regulation.

[0038] Furthermore, the power transistors Q1, Q2, and Q3 are responsible for driving the motor; their main interfaces are: Pin1 (GND), grounding; Pin2 (IO), connected to the control pin; Pin3 (IN), connected to different PWM pins of the microcontroller unit U1; Pin4 (EN), enable pin; Pin5-8 (OUT&VCC), control the power supply and output of the motor;

[0039] The motor M is controlled by Q1, Q2, and Q3, and is connected to the motor ends through three output pins to realize the driving control of the motor.

[0040] Furthermore, the resistor R1 is located in the power line and is connected in series in the circuit for current limiting protection;

[0041] The resistors R2, R3, and R4 are distributed in different signal paths and are used for voltage division, filtering, or impedance matching;

[0042] The capacitors C1, C2, C3, and C4 are used for decoupling and filtering to ensure signal stability;

[0043] The JP1 interface, the JP2 interface and the micro control unit U1 are connected via signal lines to provide control and power supply.

[0044] Furthermore, the microcontroller unit U1 is connected to Q1, Q2, and Q3 via PWM signal lines to control these power switches and thus drive the motor;

[0045] Resistors and capacitors are used for power supply decoupling and signal conditioning respectively.

[0046] Furthermore, the internal circuit of the power transistor Q1 / Q2 / Q3 is a power switch driving module, which includes logic control, a front driver, two MOSFET switches and corresponding input and output interfaces.

[0047] Furthermore, the microcontroller unit U1 integrates a high common-mode voltage sampling amplifier, samples the current of the high-side bus resistor R1, integrates an LDO to power the microcontroller, integrates a bus voltage divider circuit, and samples the voltage divider signal VBL with the ADC ANX channel inside the microcontroller.

[0048] like Figure 3 Shown is the internal circuit of power transistors Q1 / Q2 / Q3, including:

[0049] Power supply part: VCC pin is used to provide power. GND pin is used for grounding.

[0050] Input control: IN pin is used for input signal, EN pin is used to enable (enable or disable) control signal. IO pin is level-shifted or signal-conditioned by operational amplifier (OP), which may be used to amplify or compare input signal.

[0051] Logic Control Module: The logic control module receives the IN and EN signals and decides whether to turn on the driver based on these inputs. The logic control module is connected to the Pre-Driver to control the subsequent driver section.

[0052] Pre-Driver: The pre-driver controls the gate drive signals of the two MOSFETs and is used to control the subsequent power output part. Its input signal comes from the logic control module, which is responsible for applying the appropriate voltage to the MOSFET gate to control on or off.

[0053] Power MOSFET: There are two power MOSFETs in the circuit, one connected to VCC and the other connected to GND. These two MOSFETs are driven by Pre-Driver to control the output state of the OUT pin. This structure is commonly used in H-bridge or half-bridge drive circuits to control high current output.

[0054] Output section: The OUT pin is used to output signals or drive loads. Depending on the IN, EN, and IO input signals, the output state may be high (close to VCC) or low (close to GND), which can control external loads.

[0055] This circuit is a controller with MOSFET power driver. The conduction of two MOSFETs is controlled by the logic control module and the pre-driver, and finally the output state of the OUT pin is controlled to drive the external load. This type of circuit is widely used in motor control, switching power supply or other scenarios that require high current switching.

[0056] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", "connect", and "fix" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0057] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various equivalent changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A three-phase current sampling circuit of an integrated high-side MOS internal resistance power module, characterized in that: The circuit includes: a microcontroller unit U1 integrating high-side sampling operational amplifier + LDO + power supply voltage sampling, and a power transistor Q1 / Q2 / Q3 integrating high-side MOS internal resistance sampling; The microcontroller unit U1 is connected to the JP1 interface, the JP2 interface, the power transistors Q1, Q2, Q3, the resistors R1, R2, R3, R4, and the capacitors C1, C2, C3, C4 respectively; the motor M is connected to the power transistors Q1, Q2, Q3 for control; The JP1 interface includes: Pin1 (VCC), a power supply pin, connected to the positive pole of the power supply; Pin2 (GND), a ground pin; Pin3 (VSP), connected to Pin6 of the micro control unit U1; Pin4 (FG), connected to Pin7 of the micro control unit U1; Pin5 (BRK), connected to Pin8 of the micro control unit U1; The JP2 interface includes: 5V (Pin1), connected to Pin3 of the micro control unit U1, which is a 5V power input; GND (Pin2), connected to ground; SWDIO (Pin3), connected to Pin4 of the micro control unit U1; SWCLK (Pin4), connected to Pin5 of the micro control unit U1; The micro control unit U1 includes: Pin1 (VCC), power input; Pin2 (GND), ground; Pin3 (5V), 5V power input; Pin4 (SWDIO), connected to JP2-3, used for debugging interface; Pin5 (SWCLK), connected to JP2-4, debugging clock interface; Pin6 (VSP), connected to JP1-3; Pin7 (FG), connected to JP1-4; Pin8 (BRK), connected to JP1-5; Pin9 (I / O): connected to R4 resistor and grounding capacitor; Pin10 (PWM2), connected to Pin3 of Q3; Pin11 (AN2): connected to the inside of the micro control unit U1; Pin12 (PWM1), connected to Pin3 of Q2; Pin14 (PWM0), connected to Pin3 of Q1; Pin16 (VRI), connected to VCC.

2. The three-phase current sampling circuit of an integrated high-side MOS internal resistance power module according to claim 1, characterized in that: The power transistors Q1, Q2, and Q3 are responsible for driving the motor; their main interfaces are: Pin1 (GND), grounding; Pin2 (IO), connected to the control pin; Pin3 (IN), connected to different PWM pins of the microcontroller unit U1; Pin4 (EN), enable pin; Pin5-8 (OUT&VCC), control the power supply and output of the motor; The motor (M) is controlled by Q1, Q2, and Q3, and is connected to the motor ends through three output pins to realize the driving control of the motor.

3. The integrated high-side MOS internal resistance power module three-phase current sampling circuit according to claim 1, characterized in that: The resistor R1 is located in the power line and connected in series in the circuit for current limiting protection; The resistors R2, R3, and R4 are distributed in different signal paths and are used for voltage division, filtering, or impedance matching; The capacitors C1, C2, C3, and C4 are used for decoupling and filtering to ensure signal stability; The JP1 interface, the JP2 interface and the micro control unit U1 are connected via signal lines to provide control and power supply.

4. The integrated high-side MOS internal resistance power module three-phase current sampling circuit according to claim 1, characterized in that: The microcontroller unit U1 is connected to Q1, Q2, and Q3 via PWM signal lines to control these power switches and thus drive the motor; Resistors and capacitors are used for power supply decoupling and signal conditioning respectively.

5. The three-phase current sampling circuit of the integrated high-side MOS internal resistance power module according to claim 4, characterized in that: The internal circuit of the power transistor Q1 / Q2 / Q3 is a power switch driving module, which includes logic control, a front driver, two MOSFET switches and corresponding input and output interfaces.

6. The integrated high-side MOS internal resistance power module three-phase current sampling circuit according to claim 1, characterized in that: The microcontroller unit U1 integrates a high common-mode voltage sampling amplifier, samples the current of the high-side bus resistor R1, integrates an LDO to power the microcontroller, integrates a bus voltage divider circuit, and samples the voltage divider signal VBL with the ADC ANX channel inside the microcontroller.