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GR716-DS-UM, May 2019, Version 1.29
92
www.cobham.com/gaisler
GR716
9.2.4
Access control
N/A
Table 77.
GR716 Crystal configuration examples
GR716 Device
Crystal
Crystal Frequency
Load Capacitance
1) 2)
GR716-XX-AAAA
HC49US
5Mhz to 25MHz
20pF
GR716-XX-AAAB
RAKON T807
16Mhz to 25MHz
30pF
RAKON T1507
5Mhz to 10MHz
30pF
ABMM2
10MHz
18pF
JXS32-8-10/10-FU-WA-LF
20MHz
2)
Note 1:
The total crystal load capacitance should take into account the PCB stray capacitance
and the input capacitance of the GR716 device on XO pins to ground. The XO input
pins to ground are typically 4 pF. E.g. Assuming a crystal with load capacitance of
20pF and PCB stray capacitance would require C
X1
= C
X2
= 33 pF
Note 2:
Due to the known issue with weak XO amplifier on revision GR716-XX-AAAA and
GR716-XX-AAAB the C
X1
and C
X2
is chosen carefully for this specific revision.
The C
X1
should be = 6.8 pF and the C
X2
= 22 pF