提出了一种用于LLC模式LED驱动的精确调光补偿算法及电路。在开启过程中,积累LED电流实际值与预设值的偏差量,在PWM关断信号出现后,释放积累电荷量并推迟环路关断,实现精确调光补偿效果。基于此原理,设计了精确调光补偿算法电路,该算法电路包括与误差放大器关联的跨导放大器、误差积累与释放电路、PWM信号延展电路。对采用该算法电路的LLC系统进行仿真,结果表明,在恒流过程无偏差的情况下,有效PWM占空比延展了3.3%,即调光精度至少提高3.3%。 An accurate dimming compensation algorithm and circuit for LLC mode LED driver are proposed. During the turn-on process, the deviation between the actual value of the LED current and the preset value is accumulated. After the PWM turn-off signal appears, the accumulated charge amount is released and the loop turn-off is delayed, thereby achieving accurate dimming compensation effect. Based on this principle, an accurate dimming compensation algorithm circuit is designed. The algorithm circuit includes a transconductance amplifier associated with the error amplifier, an error accumulation and release circuit, and a PWM signal stretching circuit. The simulation of the LLC system using this algorithm shows that the effective PWM duty cycle can be extended by 3.3% in the case of constant current without deviation, that is, the dimming accuracy can be improved by at least 3.3%.