A 63% Efficiency 1.29-W Single-Link Multiple-Output (SLiMO) Isolated DC-DC Converter Using FPC Micro-Transformer With Local Voltage and Global Power Regulations

This article introduces a small form-factor single-link multiple-output (SLiMO) isolated dc-dc converter design. The proposed design provides two regulated voltage rails with a single low-cost standard flexible printed circuits (FPCs)-based micro-transformer design with 6 mm diameter and 0.13 mm thickness, achieving both local voltage regulation at the secondary side and global power regulation across the isolated barrier at the primary side. A digital discrete frequency control is introduced as the control scheme for the global power regulation, and a current-rotation-based control is introduced as the control scheme for the local voltage regulation of the active rectifier for the two outputs. The proposed SLiMO converter is fabricated in 0.18- \mu m CMOS using 3.3-V IO devices, achieving a 63% peak efficiency, a 1.29-W maximum output power, and a fast load-transient response.