一种高精度高转换效率的LED驱动电路

基于HHNEC 0.35μm 40 V BCD工艺,采用峰值电流检测模式的脉冲宽度调制方式,设计了一款能在8～42 V的输入电压范围内,-40～125℃的温度范围内正常工作的高转换效率、高输出电流精度的发光二极管(LED)驱动电路,版图面积为925.3μm×826.8μm。利用带负反馈的预稳压电路为基准源电路和线性稳压器提供稳定的工作电压,新颖求和型CMOS基准电流源提供低温漂、高精度的偏置电流,带预抑制电路的基准电压源提供高精度的参考电压,提高了输出电流的精度。仿真结果表明,在典型工艺角TT下,当输入电压为40 V,驱动9个LED,输出电流为400 mA时,该LED驱动电路转换效率为95.8%,输出电流精度为1.75%。

LED Driver Circuit with High Accuracy and High Conversion Efficiency

A light emitting diode(LED) driver circuit with high conversion efficiency and high output current precision was designed based on HHNEC 0.35 μm 40 V BCD process and pulse width modulation of peak current detection mode. The LED driver circuit can work normally with an input voltage range of 8-42 V in the temperature range of-40-125 ℃. The layout area is 925.3 μm×826.8 μm. The prestabilized circuit with negative feedback was used to provide stable operating voltage for reference source circuit and linear regulator.The novel summation CMOS reference current source was use to provide the bias current with low temperature drift and high precision. And the reference voltage source with pre-suppression circuit was use to provide the reference voltage with high precision which improves the accuracy of the output current. The simulation results show that the conversion efficiency of the LED driver circuit is 95.8%, and the output current precision is 1.75% under the typical TT process corner, when the input voltage is 40 V, driving 9 LEDs, and the output current is 400 mA.