Cycle by cycle closed loop control techniques for SMPS based laser diode driver

摘要

Laser diode (LD) pumped solid state lasers have progressed spectacularly over last decade and therefore LD drivers in wide power ranges have grown up as an essential shelf item for the designers of solid state lasers. As for the SMPS based LD driver, a couple of non linear and multi-loop control techniques based on cycle by cycle control are shown to favor the sensitive nature of LD, and protect it from exceeding its safe operating area (SOA) in steady state as well as transient conditions. At the same time, the system dynamics of the LD driver is made significantly faster due to feedforward based inner control loop that acts every cycle. In this paper, we present the design of controllers based on these two techniques for an application to a LD driver based on off line single stage forward converter with a third order output filter. We compare the techniques based on various practical issues and discuss an application to a practical laser diode driver.