Cross-Platform Experimental Validation of Multi-Stage Adaptive Gate Driving for MOSFET Switching Loss Reduction in Transformer Boost Circuits

In high-step-up ratio converters for portable battery-powered devices, MOSFET switching loss limits efficiency and thermal design. This paper evaluates a multi-stage adaptive gate driver (MS-AGD) after transfer from a 900 V SiC MOSFET high-step-up converter to a 25 V Si MOSFET transformer-based boost circuit. The MS-AGD detects the Miller plateau by differential sensing and controls gate current in four stages through cascode current mirrors. The target-platform comparison combines measured switching waveforms with a temperature-based ζ coefficient and an apparent Ron−effective indicator under a fixed device, load, fixture, pulse sequence, and thermal path. Total switching energy is not determined directly. Tests at 15 frequency points from 23.26 to 125 kHz show that drain-source voltage reaches its valley in about 500 ns with MS-AGD rather than about 1300–1450 ns with fixed-resistor drive and that the MOSFET package-temperature rise is reduced at all tested points by about 25% on average. The fitted apparent thermal-electrical indicator is also lower. These mutually consistent waveform and thermal results indirectly support a reduced turn-on switching-loss contribution while avoiding interpretation of ζ or apparent Ron−effective as direct measurements of total switching loss or instantaneous channel resistance.