A frequency servo SoC with output power stabilization loop technology for miniaturized atomic clocks

A frequency servo system-on-chip (FS-SoC) featuring output power stabilization technology is introduced in this study for high-precision and miniaturized cesium (Cs) atomic clocks. The proposed power stabilization loop (PSL) technique, incorporating an off-chip power detector (PD), ensures that the output power of the FS-SoC remains stable, mitigating the impact of power fluctuations on the atomic clock's stability. Additionally, a one-pulse-per-second (1PPS) is employed to synchronize the clock with GPS. Fabricated using 65 nm CMOS technology, the measured phase noise of the FS-SoC stands at −69.5 dBc/Hz@100 Hz offset and −83.9 dBc/Hz@1 kHz offset, accompanied by a power dissipation of 19.7 mW. The Cs atomic clock employing the proposed FS-SoC and PSL obtains an Allan deviation of 1.7 × 10−11 with 1-s averaging time.