Design of High-Power White LED Drive Chip with Fully Integrated PWM Dimming Function

摘要

A novel high-power white Light Emitting Diodes (LED) drive chip with fully integrated PWM dimming function has been implemented in this paper. The chip can be easily used in any application environment which needs a high integration or avoids electromagnetic interference (EMI), for it can accomplish LED drive and on-chip dimming with very simple peripheral interface circuit. Since Pulse Width Modulation (PWM) is used as the dimming mode, the drive chip can get a wide dimming range without color shift. At the same time, a capacitor-less Low Dropout Linear Voltage (LDO) Regulator is used as a compact and efficient power conversion circuit to ensure the stability of the output. The circuit is simulated with CSMC 0.5μm mixed signal models, and the results show that the chip can operate normally.