This work presents a Gallium Nitride (GaN) based point of load (POL) DC-DC converter with a reconfigurable series-parallel hybrid topology and a digital programmable control chip. Depending on the input voltage and output current, the converter can be reconfigured to series capacitor buck topology for optimized efficiency. To achieve wide dynamic range of operation, an on-time ratio configuration is proposed for optimizing zero-voltage-switching at different IO. The IC prototype is fabricated in TSMC 0.18μm high voltage process. The converter achieves 83.7%/87.8%/90.7% peak efficiency at 48V/24V/12V-to-1V conversion and >80% efficiency over 26x load range (0.3A-8A).
