iC-WJB EVAL WJ1D

Description

The iC-WJB device is a driver IC for laser diodes in continuous or pulsed operation of up to 300 kHz. The wide power supply range of 2.7 to 6 V and the integrated reverse battery protection allows for battery operation with two to four AA/AAA cells. The laser diode is activated via switching input IN. A control to the average value of the optical laser power (APC) and integrated protective functions ensure nondestructive operation of the sensitive semiconductor laser. The IC contains protective diodes to prevent destruction due to ESD, a protective circuit to guard against over temperature and under voltage and a soft-start circuit to protect the laser diode when switching on the power supply. Short-term reversed battery connection destroys neither the IC nor the laser diode. An external resistor at ISET is employed to adapt the APC to the laser diode being used. The capacitor at CI determines the recovery time constants and the starting time. A watchdog circuit monitors the switching input IN. If IN remains low longer than preset by the capacitor at CWD, the capacitor of the APC is discharged at pin CI. This ensures that the current through the laser diode during the next high pulse at input IN is not impermissibly high.

Features