Pairing the lowest power atomic clock (CSAC) with the spectral purity of an OCXO has enabled an exceptionally stable oscillator. The Microchip LN-CSAC acts as a frequency and timing subsystem, while providing limited size, weight, and power. It accepts a 1PPS input that may be used to synchronize the unit's 1PPS output to an external reference clock within ±100 ns accuracy or discipline its phase and frequency to within 1 ns and 1.0 × 10–12, respectively. Phase Noise—sine wave ≤–85 dBc/Hz at 1 Hz ≤–120 dBc/Hz at 10 Hz ≤–140 dBc/Hz at 100 Hz ≤–145 dBc/Hz at 1 kHz ≤–150 dBc/Hz at 10 kHz ≤–155 dBc/Hz at ≥100 kHz