A digitally compensated 1.5 GHz CMOS/FBAR frequency reference

A temperature-compensated 1.5 GHz film bulk acoustic wave resonator (FBAR)-based frequency reference implemented in a 0.35 ¿m CMOS process is presented. The ultra-small form factor (0.79 mm × 1.72 mm) and low power dissipation (515 ¿A with 2 V supply) of a compensated FBAR oscillator present a promising alternative for the replacement of quartz crystal frequency references. The measured post-compensation frequency drift over a 0-100°C temperature range is <±10 ppm. The measured oscillator phase noise is -133 dBc/ Hz at 100 kHz offset from the 1.5 GHz carrier.