November 14, 2014 // By Graham Prophet
IQXV-80 and IQXV-81 series LVPECL/LVDS Voltage Controlled Crystal Oscillators (VCXOs) are intended for applications such as 10G & 40G Ethernet, SDH/SONET, WiMax, WLAN and digital imaging.

These devices are available in a frequency range from 40 to 170 their range. Low-Voltage Positive Emitter-Coupled Logic (LVPECL) outputs are typically chosen for their compatibility with high-speed ICs whilst Low Voltage Differential Signalling (LVDS) is similar but with lower power consumption.

Packaged in 3.2 x 2.5 mm industry standard 6-pad ceramic package, with a hermetically sealed metal lid to reduce EMI radiation, the IQXV-80 has an LVPECL output while the IQXV-81 offers LVDS. Both series operate from a 3.3V power source and are available with stabilities of ±25ppm or ±50ppm over an operating temperature range of -40 to 85C. In either case the frequency can be adjusted externally by the application of a control voltage (1.65 ±1.5V) which can pull the output frequency by a minimum of ±80 ppm. This allows for absolute frequency adjustment and a correction for crystal ageing.

Both variants offer tri-state capability which can aid the testing and isolation of the circuit during alignment and upgrading. Phase jitter is extremely low for devices of this nature at less than 1psec RMS (12 kHz to 20 MHz).