A PVT-tolerant relaxation oscillator in 65nm CMOS
Cimbili Bharath Kumar
Date of Issue2017-02-01
School of Electrical and Electronic Engineering
One of the major problems with integrated oscillators is that of stability against the process, supply and temperature variations. The proposed circuit architecture presents a fully-integrated CMOS relaxation oscillator (ROSC) using a process-voltage-temperature (PVT) insensitive current reference generator. The oscillator circuit is based on a conventional ROSC architecture which includes a PVT insensitive current and a voltage reference circuit, two comparators, two capacitors and an output logic circuit which consists of a SR latch and a frequency divider. The oscillator is designed to generate a clock frequency of 64.4kHz in 65nm CMOS technology. The Monte-Carlo simulation results have shown that the ROSC is able to achieve 3.66% in the process sensitivity (σ/μ). The output frequency variation is 1.71% over the temperature range from ‒20oC to 100oC and 0.73% over the supply variation from 1.2V to 2V. The power consumption of ROSC is 4.32μW at 1.2V supply. It has displayed better figure-of merit (FOM) against PVT variations with respect to other reported prior-art works.
DRNTU::Engineering::Electrical and electronic engineering