A Dual-Output Reconfigurable Shared-Inductor Boost-Converter/Current-Mode Inductive Power Management ASIC with 750% Extended Output-Power Range, Adaptive Switching Control, and Voltage-Power Regulation

This paper describes a dual-output, reconfigurable integrated power management (IPM) ASIC for inductive power delivery. The proposed ASIC operates either as a current-mode (CM) rectifier or a boost converter by sharing the receiver (Rx) coil $(L_{Rx})$ to improve performance of inductive power transmission against the variations of Rx input power $(P_{Rx})$ and dual-output DC power $(P_{L}+ P_{Hv})$ . Conventional IPM structures either fail to generate regulated outputs (e.g., $V_{L}$ and $V_{Hv}$ ) when the required $P_{L}+ P_{Hv}$ exceeds $P_{Rx}$ or suffer from low power-conversion efficiency (PCE) when $P_{Rx}$ exceeds $P_{L}+ P_{Hv}$ due to voltage regulation and protection. To overcome these challenges, the proposed ASIC offers the unique capabilities of 1) generating multiple regulated outputs $(V_{L}= \text{2.6}\,\text{V},\,V_{Hv}= \text{3.9}\,\text{V})$ directly from $L_{Rx}$ with single-stage conversion, 2) efficient CM operation with active rectification, enabled by adaptive switching control (ASC), 3) charging a large capacitor ( $C_{S}$ ) with the purpose of operating as a shared-inductor boost converter (SBC), transferring energy from $C_{S}$ to $C_{L}$ and $C_{Hv}$ , when $P_{Rx} , and 4) efficient voltage-power regulation (VPR). A proof-of-concept chip was fabricated in a 0.35-μm 2P4M standard CMOS process occupying 1.35-mm2 active area. In measurements, the proposed ASIC was able to successfully provide regulated $V_{L}= \text{2.6}\,\text{V}$ and $V_{Hv}= \text{3.9}\,\text{V}$ despite significant variations in $P_{Rx}$ , $P_{L}$ , and $P_{Hv}$ . Moreover, the chip extended the peak output power range by 750% and improved the PCE by 1.3 times and 8.1 times thanks to the ASC and VPR, respectively.