Euroquartz HC35 crystals, which are ideal for aerospace and defence applications, can be despatched within 15 days of order as standard with shorter leadtimes of just a few days available to special order (depending on specification required and factory loading). Crystals can be produced at any frequency from 8 to 40MHz in fundamental mode and up to 260MHz in overtone modes.
The crystals are housed in the industry standard TO5 (HC35) resistance weld, hermetically sealed package and offer a wellproven design with a long history of design-ins among military and aerospace applications where durability and ability to maintain close tolerances in a hostile environment are desirable qualities. The TO5 housing is well-known for transistors and, when used to house crystals, the TO5 can has the advantage of providing a three-point crystal mounting scheme, ruggedising the crystal for shock and vibration environments.
Calibration tolerances from ±3ppm can be achieved and temperature stabilities of ±5ppm over -20 to +70°C are available (±3ppm over -10 to +60°C). Supplied in bulk packs, all crystal parameters can be customer specified without delaying the design. Common specifications include maximum shunt capacitance (C0) of 4pF, drive level of 100µW maximum, shock of 100g/6ms, vibration of 10g/1.5mm (10 to 500Hz, 3 axis) and ageing of ±2ppm maximum for first year, ±1ppm typical per year thereafter. Various operating temperature ranges are available including 0 to 55°C and from -55 to +125°C.
Euroquartz Frequency Products Ltd, Crewkerne, Somerset TA18 7HE, UK