光纤放大器抽运模块LD驱动电流源设计

Design of LD current drivers of pump-modules in fiber amplifiers

为了实现光纤放大器的抽运模块驱动电源精度高、纹波系数小、转换效率高并具有一定保护功能,设计了半导体激光器的驱动电流源。该电流源由驱动、串口控制等模块组成。采用基于LM2676的开关转换方式,构建了转换效率较高的恒流源系统,并应用于LD驱动。经测试,通过LD的电流最大为2.5A,输出电流精度达到0.1%,转换效率可达85%以上,LC滤波电路使输出电流纹波减少至0.5mA;具有串口通信电流源控制系统,能够实现对驱动电流值的远程读取与设置。结果表明,该电流源达到理论设计要求,可应用于光纤放大器抽运模块。

In order to obtain high precision, high efficiency and low ripple current drivers in pump-modules of fiber amplifiers, a new laser diode （LD） driving circuit, composed of modules of driver and serial interface and so on, was designed. A switching power-converter current source based LM2676 was designed to drive LD at higher conversion efficiency. The circuit is capable of delivering up to 2. 5A current to a laser load with precision of 0. 1% , efficiency larger than 85% and current ripple of 0. 5mA because of a LC filter, Meanwhile long-distance reading and setting of the pump-module LD driver can be achieved by the design of serial device circuit control system. Results indicate that the circuit meets the theory design demands and can be applied in pump-modules of fiber amplifiers.