Design Of Brushless DC Motor Driver Chip With Built-in Hall Detectio

With the improvement of people’s living standards,there is an increasing demand for intelligent products and their functional requirements.The sweeping robots based on brushed DC motors have drawbacks such as high noise,high power consumption,and short life.However,compared to brushed DC motors,brushless DC motors have the advantages of longer life,lower power consumption,and lower noise.On the other hand,the robot that integrates sweeping and mopping has become a hot topic at present.Therefore,a brushless DC motor driver chip was designed,which can be applied to robots that integrate sweeping and mopping.A three-phase brushless DC motor driver chip with integrated Hall detection was designed based on the Huahong 0.18 μm Bipolar-CMOS-DMOS process,which has the function of detecting and processing Hall signals.Compared with the structure of multi-stage interconnection,hall hysteresis amplifiers have the characteristics of simple structure and easy implementation.The chip consists of Hall detection circuit,LDO,charge pump circuit,logic control circuit,oscillator,overtemperature,low-voltage protection circuit,and interface circuit.At the same time,in high-voltage LDO circuits,there is no need for pre-voltage structure,and LDMOS are directly used to achieve voltage reduction.Moreover,it has PWM control and constant voltage mode.In PWM mode,the duty cycle of the PWM signal and the frequency of PWM can adjust the motor speed,Finally the chip achieves a voltage operating range of 8-40 V.Simulation verification by Cadence shows that the working voltage of the chip is8-40 V and the maximum output current of the chip is 2 A.The chip can handle Hall signals with frequencies ranging from 0-50 KHz with signal amplitudes as low as 20 m V.Under the analog noise simulation,the output is basically unaffected by noise,and the total on-resistance is 1 Ω under normal temperature conditions.The internal LDO has an input voltage of 8-40 V and has strong anti-interference ability.In addition,there is a low-voltage detection circuit at the voltage generated by the LDO,when the voltage is lower than 4.15 V,turn on the low-voltage protection,the low-voltage protection has0.3 V hysteresis,when the voltage returns to 4.45 V,the low-voltage protection circuit is closed.On the other hand,the oscillator can generate a frequency of 3 MHz as a digital logic clock signal and provide the charge and discharge frequency of the charge pump.In addition,the operating temperature of the chip is higher than 157 °C,the overtemperature protection circuit is turned on,when the temperature returns to 122 °C,the chip resumes normal operation,an overcurrent limiting circuit limits the output current by up to 2 A.Finally,the effects of supply voltage,duty cycle and frequency on motor speed at PWM of 50 KHz are verified.The chip layout was designed according to the circuit,and the DRC and LVS verification were completed.The motor driver chip designed has complete functions,good performance,and various protective circuits,which can be applied to robots that integrate sweeping and mopping.