A Low Power 900 MHz ISM Band CMOS Ring Oscillator with Wide Tuning Range Control

this paper presents a differential delay cell with a positive feedback to increase the operation speed alone with power reduction. A voltage controlled oscillator using twostagedelay cells working with a 1.2 V power supply is implemented in 0.18μm CMOS process to verify the efficiency ofthe proposed differential delay cell. The VCO topology exhibits a wide range of operation frequency from 600 MHz to 1390 MHz with a 790 MHz/V VCO gain (Kvco). A tuning range of58.3% is obtained for the full range of control voltage from 0 to 1.2 V. The post-layout simulation-results indicate a phase noiseof -91 dBc/Hz at 1MHz offset at 900 MHz carrier with a power consumption of 47.57 μW.

Keywords:

CMOS ring oscillator , differential delay cell , phase noise , voltage-controlled oscillator (VCO) , tuning range