A novel structure for portable digitally controlled oscillator

Abstract

A new structure for digitally controlled oscillator (DCO) is presented in this paper. The proposed structure of DCO is implemented by standard cell library, and with the help of C program and HSPICE simulator, the DCO can be designed in a systematic way. The DCO, which is realized on a IP4M 0.35-/spl mu/m. CMOS process, has a target frequency at 250 MHz, and it covers three process, voltage, and temperature (PVT) conditions: (FF, 3.6 V, 0/spl deg/C), (TT, 3.3 V, 25/spl deg/C), and (SS, 3.0 V, 100/spl deg/C). The DCO, which is realized on a IP5M 0.25-/spl mu/m CMOS process, has a target frequency at 400 MHz, and it covers three PVT conditions: (FF, 2.75 V, 0/spl deg/C), (TT, 2.5 V, 25/spl deg/C), and (SS, 2.25 V, 100/spl deg/C). The DCO has 32-bit control and achieves LSB resolution under 1 ps.