A 90nm CMOS wide-band voltage-controlled ring oscillator for digital TV-tuner

A voltage-controlled ring oscillator in 90 nm CMOS technology with ultra wide-band and low phase noise for digital TV-tuner is presented. By introducing pre-amplifying transistors to get novel four outputs delay stage, tuning range is greatly widened. Pre-charging transistors with optimized control method decrease phase noise without increasing parasitic capacitances. The oscillator can be operated from 38 MHz to 1.38 GHz, while worst phase noises are -107 dBc/Hz at 1 MHz offset and -85 dBc/Hz at 100 KHz offset in full frequency range. It maximally consumes 11.1 mA with 1.8 V supply voltage.