A digital clock frequency doubler capable of handling large variation in input duty cycle and PVT (Process, Voltage and Temperature) is presented. Unlike the conventional clock frequency doublers, the proposed circuit doesn't require 50% duty cycle for doubling the input clock frequency and consumes lower silicon area. A digital algorithm is used to generate output frequency and an inbuilt PVT compensation mechanism ensures good frequency stability if there is any change in PVT. The circuit has been designed in 90nm CMOS process with input frequency range of 10MHz to 30MHz and silicon results show less than 0.2% of average frequency error. © 2005 IEEE.