传统的开关型LED驱动电源中含有大电解电容和高频变压器,导致LED驱动电源的体积庞大且使用寿命较短.分段式线性恒流驱动电源可以避免使用大电解电容和高频变压器.设计了一种新型的分段线性恒流LED驱动电源,利用整流之后的高压脉动直流电压的变化,自适应地控制LED灯珠分阶段恒流工作.除整流桥和采样电阻外,整个驱动电路可实现单芯片集成,有效缩小了体积、延长了寿命.电路中还设计了智能拓展端口,可实现智能化控制.基于华虹宏力0.5 μm 700 V BCD工艺对电路进行了仿真验证,在0～311 V周期脉动高电压输入条件下,驱动芯片分四阶段恒流工作,输出最大恒定电流可达97.17 mA,在恒流阶段,电流的瞬态精度误差仅为0.031％.仿真结果表明,该LED驱动电路各指标参数均满足预期要求.%There are electrolytic capacitors with large value and high frequency transformers in traditional switch-mode LED drivers.They will result in large size and short life of a LED driver.A novel segmented linear constant current LED driver which avoids using electrolytic capacitors and high frequency transformers was proposed.It adapts to automatically control LED working with constant current in stages that high voltage pulsating DC voltage after rectification.The LED driver circuit with smaller volume and longer service life can be integrated in a monolithic chip except the rectifier bridge and the sampling resistor.In addition,this driver will achieve intelligent control through an extended pin.The circuit of this LED driver was designed and simulated based on HG 0.5 μm 700 V BCD process.Simulated results show that the driver circuit works in four stages under the condition of high pulse input voltage of 0～311 V cycle,the maximum constant output current is 97.17 mA and the current transient precision error is only about 0.031％.These simulated results indicate that all parameters of this high-voltage regulator are validated.
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