光纤放大器抽运模块LD驱动电流源设计

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。

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

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 0.5 mA 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.