结合具体的LED驱动电路控制芯片,对峰值电流控制型、平均电流控制型、单级单开关非隔离型LED驱动电路的原理、优缺点和性能改进措施做了论述。给出了采用频率抖动技术的LED驱动电路的传导EMI峰值及平均值测量结果和基于IR2540的平均电流控制型LED驱动电路的工作波形及效率测量结果,并对脉冲恒流源型LED驱动电路的原理做了简要的介绍,最后从恒流精度、效率、成本3个方面综合分析了LED驱动电路的发展趋势。

Taking specific LED driving IC for example,the principle,advantages,disadvantages and performance improvement measures of peak current control,average current control and single-stage single-switch no-isolated LED driving circuit are discussed. The conduction EMI peak and the average test results of LED driving circuit using the jitter frequency technology is given. The work waveform and efficiency test results of LED driving circuit of average current control based on IR2540 are also given. The principle of the pulsed constant current supply LED driving circuit is briefly introduced. At last the meta-analysis about the development trend of LED driving circuit is done from the three aspects of constant current precision,efficiency and cost.