A high-speed AOI LED strobe driver with a fully soft-switched isolated single-input dual-output converter

This paper proposes a switching-based high-speed LED strobe driver circuit (HLSDC) and a fully soft-switched single-input dual-output converter (SIDOC) for automatic optical inspection (AOI). The HLSDC employs two input voltage sources to achieve a high current slew rate while maintaining a low switching frequency. To meet the dual-voltage-source requirement, the proposed SIDOC is further developed. The SIDOC provides two independently regulated isolated output ports with a reduced component count. In the SIDOC, all semiconductor devices operate under soft-switching conditions, thereby reducing switching losses. Theoretical analysis, design guidelines, and control strategies are presented for both the HLSDC and SIDOC. Moreover, 100-W HLSDC and 150-W SIDOC prototypes were built to verify the theoretical analysis and feasibility. Experimental results show that the HLSDC achieves a 9-μs current rise time under a 5-kHz dimming frequency with an 80-kHz switching frequency. The measured peak efficiencies of the HLSDC and SIDOC reach 96.75% and 95.7%, respectively.