A fast start-up 3GHz–10GHz digitally controlled oscillator for UWB impulse radio in 90nm CMOS

Abstract

A digitally controlled ring oscillator, key component of a UWB transceiver, is presented. The design supports the IEEE 802.15.4 standard for which all bands between 3 and 10 GHz can be synthesized with frequency steps as small as 4 MHz, it is to be embedded in a low power fast startup phase- aligned frequency-locked loop requiring a duty-cycled operation of the DCO with a settling time below 2 ns. The average power consumption ranges from 0.3 mW at 3 GHz up to 1 mW at 10 GHz in 90 nm IV digital CMOS.