一种用于LED驱动的恒流控制电路设计  

Design of Constant-Current Controlled Circuit for LED Driver

作　　者：王易[1] 徐祥柱[1] 黎兆宏[1] 明鑫[1] 周泽坤[1] 张波[1] 

机构地区：[1]电子科技大学电子薄膜与集成器件国家重点实验室,成都610054

出　　处：《微电子学》2012年第2期229-232,共4页Microelectronics

摘　　要：提出一种用于LED驱动的恒流控制电路,通过对一个基准电流进行放大,得到LED的输出电流;通过改变基准电流的大小,可以按比例改变输出电流的大小,即实现LED驱动的模拟调光功能。该电路对基准电流进行2 000倍的放大,基准电流可以在5～110μA的范围内变化,能满足常规LED驱动芯片模拟调光功能的要求。仿真结果表明,该电路产生的LED输出电流误差小于0.03%,对温度敏感性小,能在较大温度范围内保持正常工作,且设计了相关的修调电路,使电路的匹配性更好、精度更高。A constant-current controlled circuit for LED driver was proposed,which obtained LED output current by amplifying a reference current.So,the output current changed with the reference current proportionally,thus realizing analog dimming function of the LED driver.The circuit was designed to amplify the reference current by 2 000 times,which varied from 5 μA to 110 μA,satisfying the requirement of analog dimming for LED drivers.Simulation results indicated that the circuit had an output current error less than 0.03%,and the output current was not sensitive to temperature,and it could operate properly in a wide temperature range.In addition,trimming structures were also designed for the circuit to achieve better matching and accuracy.

关 键 词：LED驱动 恒流控制 模拟调光 

分 类 号：TN43[电子电信—微电子学与固体电子学]