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Crystal Selection
for proper FSK Modulation
with Melexis Transmitter ICs
39011 70000 01 Page 1 of 4 Crystal Selection
Rev. 002 June/03
f
spur
a
spur
> -10dB
(pass)
> 100kHz
(pass)
pass
spur
a
spur
> -28dB
(pass)
A crystal that meets FSK modulation requirements in terms of spurious suppression
Closest crystal spurious response is more than 100kHz away from main response.
All spurious responses are least > 10 dB below main response.
FSK modulation at data rates higher than 5 kbits/s is no problem.
FSK deviation can be ± 15 kHz and higher.
Figure 1: Crystal Type 13.56000 MHz / HC-49-SMD
Figure 2: Crystal Type 13.56000 MHz / HC-49-SMD
