Research And Design Of A Three-Phase Brushless DC Motor Driver Chip Based On N-Type DMOS Power Devices

With the booming development of power devices,traditional internal combustion engines are gradually replaced by electric motors,and the market has been updated with more environmentally friendly,more efficient,and better performing motors for cars,cruise ships,and large equipment in factories.As a result,there are higher standards for motor performance,efficiency,power consumption,and control intelligence,making the design of motor drive chips a research hotspot for companies and universities.In this dissertation,a three-phase brushless DC motor driver chip based on N-type DMOS power devices is designed based on the 0.35μm BCD process from Nuvoton Technology,Taiwan.The chip’s input voltage range is 8V～60V,and the power device’s typical on-state resistance is less than 400mΩ,and the average current is 2.5A.The chip converts the received Hall sensor position signal into a control signal by logic operation and is used to control the on-state and off-state of the power tube to drive the motor forward and reverse functions.The chip has an internal bandgap reference circuit to provide stable voltage and current,an LDO circuit to provide stable voltage for the internal low-voltage devices,a charge pump circuit to drive the high-side power tubes,a Hall logic decoder circuit to convert logic signals into drive control signals,an H-bridge gate drives circuit,and various protection modules.The simulation shows that the three-phase brushless DC motor driver chip designed in this thesis can work in both 60° or 120° conduction mode,and realize the functions of forward and reverse rotation,under voltage,over temperature,and over current.When the supply voltage is powered up to 60 V after 300μs,the LDO outputs a stable 5V voltage for the internal low voltage supply after 180μs,the charge pump provides 65 V gate drive voltage for the high-side power tube after 310μs,and the three-phase motor works normally after 334μs.The static power consumption of the chip is 4.5m A.In summary,the three-phase brushless DC motor driver chip designed in this thesis has an excellent performance index.