See also: Crystal
summary and Glossary of crystal terms
Below we give a brief explanantion of the more popular terms used when
describing the specifications of quartz crystals. If you need further
explanation, our engineers will be happy to help. Email:
To express normal parameters concisely we use a standard
notation of the form:
A = Calibration tolerance, expressed in parts per million (ppm)
B = Temperature stability over the temperature range, expressed in parts
per million (ppm)
C = Negative end of operating temp range, which is normally symmetrical
- 0 = 0 to +50°C
- 10 = -10 to +60°C
- 20 = -20 to +70°C
- 30 = -30 to +80°C
- 40 = -40 to +90°C
- 55 = -55 to +105°C
If the operating temperature range is not symmetrical about +25°C we
will specify both upper and lower limits i.e. -55+125. Ovened
Crystals are signified by showing the oven temperature here and the
figures 00 for temperature stability.
D = Circuit condition. A number specifies parallel resonance with a load
capacitance in pF. SR denotes Series Resonance.
E = Operating mode of crystal, where:
- F = fundamental mode
- 3 = third overtone
- 5 = fifth overtone
- 7 = seventh overtone mode
- 9 = ninth overtone mode
Frequency and holder style are shown separately as are any special parameters
such as C1,C0,L1, etc.
- 30/50/10/30-F denotes a crystal with ±30ppm calibration
tolerance, a temperature stability of ±50ppm over temperature range
-10+60°C, 30pF load capacitance and operating in fundamental mode.
- 05/10/20/SR-3 denotes a crystal with ±5ppm calibration
tolerance, a temperature stability of ±10ppm over temperature range
-20+70°C, series resonant and operating in third overtone mode.