Applying One-Comparator Counter-Based Sampling to Current Sharing Control of Multichannel LED Strings

In this paper, a fully digitalized current sharing strategy without any analog-to-digital converter (ADC) is presented and applied to light-emitting diode (LED) lighting. By doing so, the cost for digital control is reduced significantly due to no ADC used. Aside from this, LED dimming is easy to realize. Above all, the proposed current sharing method has the capability of resisting variations in input voltage and component parameter. Such a control topology is demonstrated by some experiments and hence is very suitable for LED street lighting.