The SG-8503CA and SG-8504CA, from Epson, are programmable, low-jitter crystal oscillators with two- and four-selectable output frequency options. They consist of an SPXO, PLL, and LVPECL output buffer with two- and four-selectable frequency registers. There are up to four pre-programed registers available, programmed from 50 MHz to 800 MHz (chosen by the customer) with almost 2 ppb resolution. The user then selects output frequency from one of the pre-programmed registers.

The SG-8506CA is a low-jitter, I²C programmable crystal oscillator at any frequency. The SG-8506CA consists of an SPXO, PLL, and LVPECL output buffer. The output frequency is programmable from 50 MHz to 800 MHz with almost 2 ppb resolution and can be reprogrammed via I²C bus.

The SPXO supplies a fundamental reference clock to a low-jitter fractional-N PLL and the output frequency is selected to the desired frequency by the user. Integrated phase jitter is below 0.31 ps rms (12 kHz to 20 MHz). The fractional-N PLL is also designed to fit low-power applications, therefore reducing the overall system power consumption.

The default startup frequency is set by factory or SG-Writer II.