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

A voltage-controlled ring oscillator in 90nm 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 38MHz to 1.38GHz, while worst phase noises are −107dBc/Hz at 1MHz offset and −85dBc/Hz at 100 KHz offset in full frequency range. It maximally consumes 11.1mA with 1.8V supply voltage.