ICS83905AGI ICST [Integrated Circuit Systems], ICS83905AGI Datasheet - Page 11

• Manufacturer Part Number: ICS83905AGI
• Description: LOW SKEW, 1:6 CRYSTAL INTERFACE-TO LVCMOS/LVTTL FANOUT BUFFER
• Manufacturer: ICST [Integrated Circuit Systems]

C
Figure 1A shows an example of ICS83905I crystal interface with
a parallel resonant crystal. The frequency accuracy can be fine
tuned by adjusting the C1 and C2 values. For a parallel crystal
with loading capacitance CL = 18pF, we suggest C1 = 15pF and
C2 = 15pF to start with. These values may be slightly fine tuned
further to optimize the frequency accuracy for different board lay-
83905AGI
RYSTAL
I
NPUT
Integrated
Circuit
Systems, Inc.
I
NTERFACE
A
F
http://www.icst.com/products/hiperclocks.html
18pF Parallel Cry stal
IGURE
PPLICATION
X1
C2
15p
1. C
RYSTAL
C1
15p
R1 (optional)
11
O
0
I
SCILLATOR
outs. Slightly increasing the C1 and C2 values will slightly reduce
the frequency. Slightly decreasing the C1 and C2 values will slightly
increase the frequency. For the oscillator circuit below, R1 can
be used, but is not required. For new designs, it is recommended
that R1 not be used.
NFORMATION
L
XTAL_IN
XTAL_OUT
OW
LVCMOS / LVTTL F
I
NTERFACE
S
KEW
, 1:6 C
RYSTAL
ICS83905I
ANOUT
I
NTERFACE
REV. B MAY 16, 2005
B
UFFER
-
TO
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