An input-adaptive self-oscillating synchronous boost converter for LED driving with ultra-low wide-range voltage input

An input-adaptive self-oscillating synchronous boost converter is proposed for ultra-low wide-range voltage input LED driving with tight input regulation, low cost, and high efficiency. It consists of a self-oscillation unit, a synchronous rectification unit, and an input-adaptive peak-current control unit including a blanking time control branch. In the paper, its operation principle including an input-adaptive peak-current control scheme with a blanking time control strategy is introduced. For a low-cost purpose, a prototype boost converter consisting of several commonly-used cheap components and devices was implemented for experimental verification. The experimental results show that it could not only start up successfully to lighten a white LED from the input voltage down to 0.8 V, but also have a tight input regulation with a good efficiency performance over the input voltage range from 1.2 V to 2.1 V.