A high-voltage full-wave rectifier and a high-voltage voltage doubler for converting an induced voltage on a coil to a DC voltage were demonstrated in a conventional 0.18μm CMOS process using standard 3.3V I/O devices. High-voltage operations were achieved by stacking a number of transistors with their gate voltages controlled by the induced voltages. For a 300kHz, 14.2V peak-to-peak induced voltage, the voltage doubler achieved an efficiency of 92.5% for an output voltage of 13.7V with an output power of 2.9mW.