An H-bridge Intelligent Power Driver Chip And Protection Circuit Design

Intelligent power integrated circuit(SPIC)technology successfully combines power control and processing in a single chip.With the advantages of intelligence and small size,it has established an indispensable position in the field of medium and low power processing.As one of the achievements of SPIC,the H-bridge intelligent driver chip appears to be of great research value due to the vision that people are eager to improve the quality of life through automatic control.Today,In the world dominated by science and technology,it is more necessary to study H-bridge driver technology to promote our automation process in China.With the help of 0.25 ?m BCD process,this design completed an H-bridge driver chip for DC brush motor.The chip is composed of logic circuit,drive circuit,power switch and other parts.The chip works in the range of 11 V?55 V power supply voltage,The acceleration?deceleration and braking of the motor can be controlled intelligently through PWM,Dir and Brake signals,The maximum current can reach 3.24 A in100%PWM drive mode.It can be used to drive the brush motor with peak current in this range.We first from the physical point of view of the motor mathematical modeling,to clarify the control of speed ideas.Then,the basic knowledge of H bridge is sorted out,Then the architecture of H-bridge driver chip is designed.Finally,through modular design,the design difficulties will be separated one by one,and finally the integration of each module verification.First the high voltage LDO was designed,the output pole of the error amplifier is pushed to high frequency through Source follower,Then the resistance connected to the power MOS gate is used to adjust the non-main poles and increase the power rejection ratio of the LDO.Secondly,level shift circuit with low delay and low static power consumption is realized by dynamic current method,which greatly optimizes the delay and power consumption,the load current of the bootstrap port is optimized,and the capacitance of the charge pump is reduced,thus saving the chip area.Since the delay of the high-side driver is roughly equal to that of the low-side driver,the dead zone through of H-bridge can be avoided only by compensating the logic module.In Signal magnitude Control mode,the brushed motor is simulated to drive,and the co-simulation verification and functional analysis are carried out.The results are as follows: under heavy load condition,the current is up to 3.24 A,the startup time is about100?s,and the internal integrated high and low power MOS conduction resistance is0.489 ? and 0.485 ? respectively.The time of rising and falling dead zones is 58.4 ns and 155 ns respectively,which can effectively reduce the loss of asynchronous attenuation.The turn-on and turn-off time of Miller platform were 87.73 ns and 6.6 ns.In Signal magnitude Control mode,the current increase rate in the driving stage is negatively correlated with the load current,while the current decrease rate in the continuation stage is positively correlated with the load current.Therefore,the load current can be dynamically balanced and periodically fluctuated in a certain range by controlling the driving time and continuation time of the motor,so as to control the speed of motor.After the overall simulation verification,the motor current has a good control effect.