iC-WJB
2.7 V LASER DIODE DRIVER
Rev E1, Page 2/12
DESCRIPTION
The iC-WJB device is a driver IC for laser diodes in circuit to protect the laser diode when switching on
continuous or pulsed operation of up to 300 kHz. The the power supply. Short-term reversed battery con-
wide power supply range of 2.7 to 6 V and the inte- nection destroys neither the IC nor the laser diode.
grated reverse battery protection allows for battery-
operation with two to four AA/AAA cells.
An external resistor at ISET is employed to adapt the
APC to the laser diode being used. The capacitor at
The laser diode is activated via switching input IN. CI determines the recovery time constants and the
A control to the average value of the optical laser starting time.
power (APC) and integrated protective functions en-
sure nondestructive operation of the sensitive semi- A watchdog circuit monitors the switching input IN.
conductor laser.
If IN remains low longer than preset by the capaci-
tor at CWD, the capacitor of the APC is discharged
The IC contains protective diodes to prevent destruc- at pin CI. This ensures that the current through the
tion due to ESD, a protective circuit to guard against laser diode during the next high pulse at input IN is
overtemperature and undervoltage and a soft-start not impermissibly high.
PACKAGES SO8, MSOP8 to JEDEC Standard
PIN CONFIGURATION SO8
PIN FUNCTIONS
No. Name Function
1 GND Ground
2 CWD Capacitor for Watchdog
1
8
7
6
5
KLD
AMD
IN
GND
3 CI
Capacitor for Power Control
2
CWD
4 ISET Reference Current Input
5 VCC +2.7 to +6 V Supply Voltage
3
CI
6 IN
Input
4
7 AMD Anode Monitor Diode
8 KLD Cathode Laser Diode
VCC
ISET
PIN CONFIGURATION MSOP8
1
GND
KLD
CWD
CI
AMD
IN
ISET
VCC