A 90.4% Peak Efficiency 2.5-to-5V Input 70V Output Hybrid Boost Converter for APD Bias

This article presents a high voltage conversion ratio (VCR) hybrid DC-DC converter for avalanche photodiodes (APDs) bias applications. By employing an input Series-Parallel switched-capacitor network (SCN) and an output stacked SCN, the proposed converter achieves over 67% reduction in inductor current and switch voltage stress compared with conventional boost converters. This approach enables the use of a compact inductor and lower-rated power switches, thereby improving efficiency and power density. The converter was fabricated in a 0.18-μm BCD process. It can deliver a maximum load current of 20 mA with an output voltage of 40–70 V, driven by an input voltage of 2.5-5 V. Measurement results show a peak efficiency of 90.4% and a power density of 48.5 mW/mm3.