A 0.8-V Low-Power Low-Cost CMOS Crystal Oscillator with High Frequency Accuracy

Abstract

A sub-1-V low-complexity crystal oscillator (XTO) is fabricated in 65-nm CMOS. The proposed crystal oscillator has lower power dissipation and better frequency accuracy performance than reported ones. The crystal oscillator is based on the conventional three-point Colpitts architecture. The oscillator core consists of a constant $g_{\mathrm{m}}$ gain stage, a quartz crystal and two load capacitors, followed by a single-ended self-biased band-passed amplifier. Experimental results show that the presented XTO generates a 12-MHz reference clock, achieving the phase noise of −95 dBc/Hz at 100-Hz offset frequency and the frequency inaccuracy of 1.2 ppm. The proposed crystal oscillator has an active area of 0.01 mm2 and the power dissipation is $32\ \mu \mathrm{W}$ from a 0.8-V supply.