A Four-Phase Gain Control Method to Reduce the Ignited Current Spike of the Laser Diode Using in a Laser Headlight Power Supply Unit

摘要

A laser headlight power supply unit (LHPSU) was implemented and developed to drive laser diodes. The LHPSU possessed with the current error amplifier, the buck–boost converter, and the buck–boost converter controller. In the high ambient air temperature, when the dynamic resistance of the laser diode was increased, the the buck–boost converter operated in the buck mode, and the current error amplifier adopted the proportional-integral control, the laser diode driving current caused a start-up current spike, this over-specified current spike damages to the laser diode configuration, and the optical output power would be decayed. Thus, a four-phase gain control method can be used to reduce the ignited current spike of the laser diode.