document number: 35043 for technical questions contact: frequency@vishay.com www.vishay.com revision: 28-mar-03 1 tuning fork crystal XT38T vishay dale 0.326 [8.28] max 0.122 [3.1] max 0.354 [9.0] min 0.043 [1.1] 0.012 [0.30] features ? miniature package ? low cost ? khz frequency ? tight tolerance the tuning fork type quartz crystal provides ultimate in size, performance and economic trade-offs. so it is used as a clock source in communication equipment, measuring instrument, microprocessor and other time management applications. standard electrical specifications p arameter symbol condition unit min typical max f requency range f o khz 32.768 f requency tolerance ? f/f o at 25c ppm 20 f requency coef cient k ref to 25c ppm/( ? c) 2 - 0.042 operating temperature range t opr c - 10 + 60 storing temperature range t stg c - 20 + 70 shunt capacitance c o pf 0.85 2 motional capacitance c 1 ff 1 2 4 load capacitance cl pf 12.5 insulation resistance ir 100v dc m ? 500 drive level dl w 1 aging ( rst year) fa at 25c 3c ppm - 5.0 + 5.0 equivalent series resistance(esr) rs k ? 35 dimensions in inches [millimeters] parabolic temperature curve to determine frequency stability, use parabolic curvature (k). for example: what is stability at 45c? 1) change in temperature (c) = 45 - 25 = 20c 2) change in frequency = - 0.042ppm*( ? c) = - 0.042ppm*(20) 2 = - 16.8ppm(max) - 20 - 10 0 10 20 30 40 50 60 70 - 10 - 20 - 30 - 40 - 50 - 60 ? f/f(ppm) temperature ( c) ordering information XT38T model 32.768khz frequency/khz
|
