A 12V-to-42V Input Zero-Voltage Switching Buck Converter Achieving Up to 4.5% Efficiency Improvement

A 12V-to-42V input zero-voltage switching buck converter is proposed. The proposed quasi-resonant ZVS topology greatly minimizes the conduction loss due to ZVS operation, thus enhancing the efficiency across the entire loading range. Accurate ZVS operation is achieved by implementing the circuit directly in high-voltage domain. The converter was fabricated in a $0.18 \mu \mathrm{~m}$ BCD process. It achieves $91.7 \%$ peak efficiency at $V_{\text {IN }} /$ Vout $=42 \mathrm{~V} / 5 \mathrm{~V}$ and up to $4.5 \%$ efficiency improvement within 4 A load current at $\mathrm{V}_{\text {IN }} / \mathrm{V}_{\text {out }}$ $=24 \mathrm{~V} / 3.3 \mathrm{~V}$.