GENERAL DESCRIPTION

OB3332Bx is a TRIAC dimmable high power factor, highly integrated buck/buck-boost regulator with advanced features to provide high efficiency control and high precision constant current output for dimmable LED lighting applications.

The proprietary CC control scheme is used to provide features of insensitivity to inductance and line voltage. Without external large compensation capacitor, the system can achieve high power factor with proprietary PFC control scheme.

OB3332Bx 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), thermal foldback etc.

OB3332Bx is offered in SOP-8 package.

FEATURES

Excellent TRIAC dimming performance

Low system cost and high efficiency

High PF（PF>0.9）@175~264Vac input

Support buck/buck-boost topology

High precision constant current regulation at universal AC input

Quasi-Resonant operation

Thermal foldback function for LED output current control

Insensitivity to inductance and line voltage variation

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

Over temperature protection (OTP)

APPLICATIONS

Dimmable LED lighting

TYPICAL APPLICATION

Figure 1  Buck Application circuit

Figure 2  Buck-Boost  Application circuit