ICS873990 Datasheet, PDF (10/16 Pages) Integrated Circuit Systems – LOW VOLTAGE, LVCMOS/ CRYSTAL-TO-LVPECL/ECL CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
ICS873990
LOW VOLTAGE, LVCMOS/
CRYSTAL-TO-LVPECL/ECL CLOCK GENERATOR
CRYSTAL INPUT INTERFACE
The ICS873990 has been characterized with 18pF parallel
resonant crystals. The capacitor values, C1 and C2, shown
in Figure 4 below were determined using a 25MHz, 18pF par-
allel resonant crystal and were chosen to minimize the ppm
error. The optimum C1 and C2 values can be slightly adjusted
for different board layouts.
X1
18pF Parallel Crystal
XTAL_OUT
C1
22p
XTAL_IN
C2
22p
Figure 4. CRYSTAL INPUt INTERFACE
873990AY
www.icst.com/products/hiperclocks.html
10
REV. B JUNE 13, 2005