The output of this device is generated and filtered by narrowband quartz SAW elements at 666.51 MHz. The configuration of this clock is intended to provide a pure signal for optical timing applications in noisy signal environments. The Q/Qbar differential output swing of ±1 volt about 0 vdc has symmetry better than ±1% into loads from 40 ohms to 70 ohms; determined by customer application. The long term frequency accuracy is set by an external reference source allowing this device to complete a Phase Lock Loop design without the usual noise and jitter problems associated with PLL’s.