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= 2.6 V, V_Hv= 3.9 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< P_L+ P_Hv, 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= 2.6 V and V_Hv= 3.9 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.