GENERAL DESCRIPTION
OB3337 is a dimmable buck LED lighting controller with high power factor, low THD and high constant current (CC) precision. It can achieve low system cost for the non-isolated lighting application.
The proprietary CC control scheme is used and the system can achieve high power factor with constant on-time control scheme. Quasi-resonant (QR) operation and frequency modulation greatly improves the system efficiency. The advanced start-up technology is used to meet the start-up time requirement (<0.5s). The constant output current is compensated for tolerance of transformer inductance variation. And the line compensation is built in OB3337 for high precisely constant output current control.
OB3337 offers a dimmable function, the LED current can be controlled by setting the duty cycle of PWM waveform into the DIM pin.
OB3337 offers comprehensive protection coverage with auto-recovery features including LED open loop protection, LED short circuit protection, cycle-by-cycle current limiting, built-in leading edge blanking, VDD under voltage lockout (UVLO), etc.
OB3337 is offered in SOP8 package.
FEATURES
Dimmable LED current control
High precision constant current regulation at universal AC input
High PF
Low THD
Fast start-up
Quasi-resonant and frequency modulation operation
Built-in line compensation
LED short circuit protection
LED open loop protection
Cycle-by-cycle current limiting
Built-in leading edge blanking (LEB)
VDD under voltage lockout with hysteresis
VDD over voltage protection
Over temperature protection (OTP)
APPLICATIONS
LED lighting