Design And Implementation Of High-Performance Brushless DC Motor Driver Circuit

In the electrical age,electric motors have become one of the main sources of motivation for human society,and how to drive it with higher efficiency is a popular research direction.With the development of semiconductor technology,the advantages of power integrated circuits due to their small volume,light weight,convenience,multiple function,and low cost have become the primary choice for driving motors.The motor-driven chip,as a typical power integrated circuit for power integrated circuits,is widely used in industrial control,electric vehicles,automation and other fields.Therefore,studying a high-performance motor-driven circuit is of great significance.Based on the 0.25 um 60V BCD process,this thesis designed a driving circuit for driving a brushless DC motor.The typical value of its power supply voltage is 42 V,the maximum output current can reach 2.7A,and the On-resistance of power MOSFET is less than 0.2Ω.Compared with similar products,it can output greater current under the same power supply voltage,which meets the needs of high performance.The circuit contains the power MOSFET semi-bridge,controlling logic circuit,high side power MOSFET driving circuit,low side power tube driving circuit,over temperature protection,overcurrent protection circuit with other sub-modules.This thesis first determines the function of the driving circuit through the working principle of a brushless DC motor.Based on this,it determines the architecture of the driving circuit and the function of the sub-module.The control logic circuit designed in this thesis not only have normal function but includes dead areas,brake response and the stop response.It can not only prevent the high and low power MOSFETs switch-on at the same time when the conversion is changed,but also have different responses with the brake enable signal and internal failure stop signal.The high side power MOSFET driving circuit designed in this thesis contains oscillator,charge pump,and bootstrap circuit.The charge pump continuously supply charge to the bootstrap circuit with control of the oscillator to achieve long-term high side power MOSFE conduction,which achieves maximum 2.7 A output current.It can output a high voltage control signal of 48 V with its bootstrap circuit to ensure that the high side power MOSFET working in a deep linear zone.In terms of the protection of the circuit,the current monitoring circuit is designed in this thesis,which can monitor the current of the power MOSFET in time and achieve the overcurrent protection function with 10 A threshold;and the over-temperature protection circuit can achieve 145° C alarm threshold and 170° C off threshold.Finally,this thesis completes the overall circuit construction through the Cadence Simulation software,and initially completes the layout design of the circuit.At the same time,under the condition of 42 V power supply voltage,the key performance parameters of the circuit are tested at different process angles and different temperatures.The results show that the performance of the brushless DC motor-driven circuit designed in this thesis can meet the expected target.