基于ICL7667实现步进电机高频斩波控制

为了提高小内阻步进电机驱动系统中功率MOSFET的开关速度，采用ICL7667作为功率MOSFET的驱动器，从而实现步进电机的高频斩波控制。首先，针对电阻分压式驱动电路测试和仿真中出现的功率MOSFET的漏级输出未处于截止和深度饱和状态的问题，对所采用的功率MOSFET的栅极电容特性、开关时间等进行了研究，发现栅极电容的充放电过程影响了功率MOSFET的开关速度。接着，提出了提高功率MOSFET开关速度的方法。最后，采用ICL7667作为功率MOSFET的驱动器实现了步进电机的高频斩波控制。仿真和试验结果表明：电阻分压式驱动电路在斩波频率不大于20kHz时,功率MOSFET的漏级输出能处于截止和深度饱和的状态；采用ICL7667的驱动电路，可以保证斩波频率为200kHz时，功率MOSFET的漏级输出仍处于截止和深度饱和的状态。采用ICL7667的驱动电路，使得其斩波频率比电阻分压式驱动电路的斩波频率提高了10倍，可保证小内阻步进电机在高速斩波信号的控制下正确运行。

The realization of high-frequency chopping control stepper motor based on ICL7667

ICL7667 is used as a power MOSFET drivers in stepper motor drive system,for increasing switching speed of the power MOSFET and realizing high-frequency chopping control stepper motor.First, study on the gate capacitance,switching time of the power MOSFET due to the problem of power MOSFET is not in cut-off or deep saturation.The results showed that the gate capacitance of the charge and discharge process affected the power MOSFET switching speed.Then introduce the method to increase the switching speed of the power MOSFET. Finally, ICL7667 is used as a power MOSFET driver to achieve a high-frequency chopping control stepper motor .Simulation and test results showed that:the drive circuit with voltage division by resistors in the frequency of not more than 20 kHz ,power MOSFET can to be in cut-off or deep saturation;ICL7667 can guarantee that chopping frequency of 200 kHz, the power MOSFET can to be in cut-off or deep saturation. The chopping frequency of the drive circuit used ICL7667 is increased 10 times than the drive circuit with voltage division by resistors. After using the ICL7667,stepper motor can run correctly under control of high-speed chopping signal.