A 3-MHz 17.3- $\mu$ W 0.015% Period Jitter Relaxation Oscillator With Energy Efficient Swing Boosting

This brief presents a low-power RC relaxation oscillator with low period jitter for sensor interface applications. A switched capacitor RC network is proposed to boost the timing capacitor voltage swing with high energy efficiency, so that the output jitter can be effectively reduced. An inverter-based comparator with replica bias is used for switching threshold tracking under the supply variation. Implemented in a standard 65nm CMOS process, the proposed oscillator achieved 3.0 MHz output frequency with 0.015% relative period jitter and consumed 17.3-μW power under 1 V supply voltage. The frequency variation is ±0.15% over a supply range of 0.95 V to 1.45 V and ±0.6% for temperature across 0°C to 90°C, respectively. The circuit achieved a Figure of Merit (FOM) of 161 dBc/Hz and the total energy efficiency is 5.7 pJ/cycle.