A Resonant One-Step 325 V to 3.3–10 V DC–DC Converter With Integrated Power Stage Benefiting From High-Voltage Loss-Reduction Techniques

This work presents a self-timed resonant high-voltage (HV) dc–dc converter in HV CMOS silicon-on-insulator (SOI) with a one-step conversion from 100–325 V input down to a 3.3–10 V output, optimized for applications below 500 mW, such as IoT, smart home, and e-mobility. Unlike bulky power modules, the HV converter is fully integrated, including an on-chip power stage, with only one external inductor (10 $\mu \text{H}$ ) and capacitor (470 nF). It reaches a high power density of 752 mW/cm ³ , an overall peak efficiency as high as 81%, and a light-load efficiency of 73.2% at 5 V and 50 mW output. HV loss-reduction techniques are presented and experimentally confirmed to offer an efficiency improvement of more than 32%. Integrated HV insulated gate bipolar transistors (IGBTs) are discussed and implemented as an attractive alternative to conventional integrated HV power switches, resulting in ~20% smaller area at lower losses.