A fully integrated RC oscillator with adaptive-body-biasing

Abstract

A fully integrated CMOS RC oscillator is presented. The oscillator is inverter-based. An adaptive body biasing (ABB) scheme is proposed to regulate the trip point of the decision inverter adaptively, thus alleviating the frequency variation over PVT. To achieve low power consumption all components are in the sub-threshold region. The circuit is designed in a 55-nm CMOS process with an area of 0.052mm2. The simulation result shows a temperature sensitivity of 59 ppm/°C from -40∼125°C which achieves a 72 ppm/°C reduction as compared to an oscillator without ABB. the oscillator operates at 33 kHz and consumes 183nW from a 0.6V supply.