基于太阳能发电的LED驱动电路的设计

摘要

Solar lighting system based on LED,using TI's TPS61500 as a step-up constant current con-troller,the input of 12V DC load for high power white LED single 1W 5 series as the research object,dis-cuss the design of BOOST driving circuit of LED.Through simulation and experimental verification,the soft start circuit TPS61500 internal prevent circuit generates at startup current spikes and the output volt-age is too high,exceeds the preset value;the effective value of the output current and the load in the TPS61500 EN pin PWM signal duty cycle,when the duty of PWM is relatively large large output cur-rent,when the duty ratio is small,the output current is small,therefore,can be achieved by adjusting the dimming EN pin PWM signal duty cycle to.The circuit can provide a constant driving force,so that the LED for a long time when the current is in a stable state,high reliability.%基于太阳能LED照明系统,采用了TI公司的TPS61500作为升压恒流控制器,以输入为12 V直流电,负载为5颗串联的单颗1 W的大功率白光LED为研究对象,讨论BOOST型LED驱动电路的设计.通过仿真及实验验证,TPS61500内部自带的软启动电路有效的阻止了电路在启动时产生的电流尖峰以及输出电压过高,超过预设值;输出电流的有效值与加载在TPS61500的EN引脚的PWM信号的占空比有关,当PWM的占空比较大时,输出电流大,当占空比较小时,输出电流小,因此,可以通过调节EN引脚PWM信号的占空比来达到调光的目的.该电路能提供恒定的驱动能力,使LED长时间工作时电流处于稳定状态,电路可靠性高.