滞环电流控制型大功率LED恒流驱动芯片的设计

Constant Current Driver- Chip Design of High- Power LED of Hysteresis Current Controlling Type

基于标准CMOS工艺，采用滞环电流控制模式，设计了一款新型大功率LED恒流驱动芯片。在标准CMOS工艺范围内，芯片能够实现良好的恒流驱动功能。结果表明：电源电压从3～5V变化时，输出电流保持良好的一致性，其最大值和最小值之差仅为0．075mA；随着温度的升高，输出电流先增大后减小，在电路工作的整个温度区间内，输出电流仅仅变化0．165mA；在电感为理想电感情况下，当芯片驱动7个LED灯时，效率最高可达90％以上。

Based on standard CMOS technology, a new type of High - power LED constant current driver chip is designed, using hysteresis current control mode. Within the scope of standard CMOS tech- nology, the chip can achieve good function of constant current drive. The results show that the output current keeps good consistency that the difference between maximum and minimum values is only 0. 075mA when power supply voltage changes from 3V to 5V. With the increase of temperature, the out- put current decreases after a short increase, and the circuit output current only changes 0.165mA in the whole current working temperature range. When the chip drives seven LED lamps, the efficiency can reach to 90% at most in the case of ideal inductance.