piezoelectric energy harvester, interface circuit, full-bridge rectifier, energy extraction power, Applications of electric power, TK4001-4102

This paper presents a high-efficiency piezoelectric energy harvesting and management circuit utilizing a full-bridge rectifier (FBR) designed for powering wireless sensor nodes. The circuit comprises a rectifier bridge, a fully CMOS-based reference source, and an energy management system. The rectifier bridge uses a PMOS cross-coupled structure to greatly reduce the conduction voltage drop. The CMOS reference source provides the necessary reference voltage and current. The energy management system delivers a stable 1.8 V to the load and controls its operation in intermittent bursts. Fabricated with a 110 nm CMOS process, the circuit occupies an area of 0.6 mm2, and is housed in a QFN32 package. Test results indicate that under 40 Hz frequency and 4 g acceleration vibrations, the chip’s energy extraction power reaches 234 μW, with the load operating every 3 s at a supply voltage of 1.8 V. Thus, this FBR interface circuit efficiently harnesses the energy output from the piezoelectric energy harvester.