Crystal Parameters Explained
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.
Specification Code
To express normal parameters concisely we use a standard notation
of the form:
A/B/C/D-E
where:
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 about +25°C.
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’.
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±100
ppm |
±50
ppm |
±30
ppm |
±25
ppm |
±20
ppm |
±15
ppm |
±10
ppm |
±7.5
ppm |
±5
ppm |
±4
ppm |
-40 to +90 |
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-30 to +80 |
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-20 to +70 |
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-10 to +60 |
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0 to +50 |
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Degree of
manufacturing difficulty & Priceband |
A |
B |
C |
D (*) |
| * Consult our techical department |
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
Examples
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.
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