Stable quartz oscillator uses SAW technology

Targeting LAN and SAN, Epson Toyocom recently announced the highly stable EG-4101/4121CA SAW resonator. The part combines low jitter, low phase noise, high stability, and temperature coefficients better than those of AT-cut quartz crystals. The resonator offers a frequency tolerance of ±50ppm and maximum phase jitter of 0.2ps at 622MHz over a 12kHz to 20MHz bandwidth. The device is available with LV-PECL, LVDS, and HCSL outputs. Available frequency ranges are 100MHz to 700MHz for the LV-PECL- and LVDS-output versions and 100MHz to 500MHz for the HCSL version. The resonator has a supply voltage of 2.5 to 3.3V, and current consumption ranges from a maximum of 30mA or 45mA over the supply-voltage range for the LVDS version to 80mA or 100mA for the LV-PECL version.

SAW resonators and oscillators differ from SAW filters in that the resonators use a quartz rather then a ceramic element. Don’t confuse saw resonators with inexpensive silicon or ceramic resonators, which tend to have much lower Q and worse initial accuracy and temperature coefficients. Because the SAW resonators operate at their fundamental-resonance mode, they lack the frequency jitter of conventional crystal oscillators that operate at a lower frequency; a PLL then multiplies that frequency inside the chip. The operation at fundamental mode also means that the parts do not frequency-hop as quartz crystals do.

The EG-4101/4121CA operates over a standard temperature range of -40°C to 85°C or an optional range of −40 to 90°C and comes in a 7×5×1.2-mm package.

Caption
The EG-4101/4121CA series of SAW oscillators from Epson have a flat frequency variation over temperature.

Epson Toyocom