ICS83905AMLF View Datasheet(PDF) - Integrated Circuit Systems
Part Name
Description
MFG CO.
ICS83905AMLF
Integrated Circuit Systems
'ICS83905AMLF' PDF : 14 Pages View PDF
Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS83905
LOW SKEW, 1:6 CRYSTAL INTERFACE-TO-
LVCMOS / LVTTL FANOUT BUFFER
APPLICATION INFORMATION
CRYSTAL INPUT INTERFACE, FUNDAMENTAL
Figure 1A shows an example of ICS83905 crystal interface with
parallel resonance crystal using fundamental frequency.The C1,
C2 and R1 values are suggested for the best frequency accu-
racy ppm. The optimum C1 and C2 values can be adjusted to
improve the frequency accuracy for stray capacitance of differ-
ent board layout.
X1
C2
16p
C1
10p
R1
100
XTAL_IN
XTAL_OUT
FIGURE 1A. CRYSTAL OSCILLATOR INTERFACE, (FUNDAMENTAL)
CRYSTAL INPUT INTERFACE, 3RD OVERTONE
Figure 1B shows an example of ICS83905 crystal interface with
parallel resonance crystal using 3rd overtone frequency.The C1,
C2 values are suggested for the best frequency accuracy ppm.
The optimum C1 and C2 values can be adjusted to improve the
frequency accuracy for stray capacitance of different board lay-
out. The C3 and L1 can be calculated from the given equation.
XTAL_IN
C1
10p
X1
F _ fund =
1
2π L1* C3
XTAL_OUT
C2
C3
16p
L1
FIGURE 1B. CRYSTAL OSCILLATOR INTERFACE (3RD OVERTONE)
83905AM
http://www.icst.com/products/hiperclocks.html
10
REV. A JANUARY 20, 2005
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