为了满足K98SA3F-30.00W-R型号(工作电流12A,纹波系数要求小于0.05%)半导体激光器对高功率、高稳定度的需求，设计了恒流源驱动电路，主要采用电流模式同步降压开关控制芯片LTC1625、电流检测放大芯片LT1620、功率场效应管IRF7811、数字电位器AD5231和π型滤波器使电路实现高效率、高精度、高稳定度的电流输出。通过LTspiceⅣ软件进行了模拟仿真，当电路工作在恒流模式时，输出电流在0~20A之间连续可调，最小可调步进电流值0.061A，电流纹波系数可达0.001%以下。结果表明，该恒流源完全满足K98SA3F-30.00W-R型号半导体激光器的应用要求。

In order to satisfy high power and high stability requirements of the laser K98SA3F-30.00W-R (operating current 12A, ripple coefficient requirement <0.05%), a constant-current source circuit was designed. Its output current can realize high efficiency, high precision and high stability by the chip LTC1625, LT1620, MOSFET IRF7811, digital potentiometers AD5231 and a π-type filter. The LTC1625 is a current mode synchronous step-down switching regulator and the LT1620 is a current sense amplifier. The simulation results given by LTspiceⅣ show that, when working in constant-current mode, the output current can be changed continuously from zero to 20A, the minimum variable stepping current value is 0.061A, the output current ripple coefficient of the circuit can be less than 0.001%. Results indicate the circuit can meet the application requirements of the semiconductor laser diode K98SA3F-30.00W-R.