CMOS LC oscillators using high-Q active inductors with constant-power consumption

CMOS LC oscillators using high-Q active inductors with constant-power consumption are presented. The active inductor with one feedback resistor results in a gain-boosting factor to improve the Q-value and the inductance (L) of the active inductor. Based on this high-Q active inductor, a negative resistance LC-tuned oscillator with low constant-power consumption and wide tuning-range can be achieved. Simulation results show that the improved active inductor can achieve the maximum Q-value of 1E8 and dissipate 2.5mw power consumption under 2.5 V power supply. The die size included bounding pad is about 853um × 413um. In the wide-tuning frequency range oscillator, low constant power consumption at 2.5 V power supply around 1OmW is observed. This oscillator also depicts a reasonable phase noise performance of -91dBc/Hz at 600 kHz. The phase noise from 0.8GHz to 3GHz tuning-range is less than 6dBc/Hz phase noise deviation. The small die size included bounding pad is about 965um × 482um.