A PWM Controller IC for LED Driver Used to Multiple DC-DC Topologies

A pulse width modulation (PWM) controller chip for LED driver was presented in this paper. The controller features two major operation modes, current feedback mode and constant current mode, so as to applicable to almost all DC-DC converter topologies such like buck, boost, buck-boost, flyback and SEPIC. A special error amplifier, which is composed of two sub-modules and a mode selector, was introduced to this chip to different applications. The peak current mode control with slope compensation was proposed to its control strategy. The controller integrated circuit (IC) was designed, simulated and fabricated in 1.5 mum BCD process. And both the simulation and test results were consistent with expectations well.