(A) reconfigurable thermoelectric energy harvesting PMIC for a battery-powered duty-cycling wireless sensor node

Abstract

This thesis presents a reconfigurable DC-DC converter for maximum thermoelectric generator (TEG) energy-harvesting in a battery-powered duty-cycling wireless sensor node (WSN). The converter operates in single-inductor dual-output (SIDO) boost and buck modes using a single-shared inductor. Battery-TEG pile-up buck (BTPB) and dual-phase buck-boost (DPBB) modes are proposed to maximize power extraction from the TEG. Implemented in a 65-nm CMOS process, the SIDO boost converter supplies a regulated output voltage and charges a battery in a time-multiplexing method balanced by load current. It achieves the peak end-to-end efficiency of 88.5 % and 81.1 % at maximum load condition and at no load condition, respectively. The battery-supplied buck converter achieves the peak efficiency of 93.3 %. The combination of BTPB and DPBB modes achieves up to 44 % saving in battery power by the concurrent TEG power harvesting.