A High Efficiency Active Rectifier IC for Alternating Current Energy Harvesting

This paper presents a cross-coupled PMOS with NMOS active full bridge rectifier to convert the alternating current input to direct current output. The NMOS is used as an active diode to reduce the turn-on voltage, and the low powered comparator is used as a switch to drive the gate, which reduces the voltage loss of the active rectifier and improves the conversion efficiency. The rectifier chip is fabricated by 180nm BCD process, and the effective core chip area is 1018J.lm*839J.lm. Comparing the active rectifier with Schottky diode rectifier, the measurement results show that the conversion efficiency of Schottky diode rectifier is 80.6%-95.9%. The proposed active rectifier has an input voltage range of 2.2V-20V, current consumption at operation of 115.4µA, the charging current is about 47mA, the output power is about 409mW, and has a high conversion efficiency of about 92-97.5^%.