ICS843021I-01 Datasheet, PDF (9/14 Pages) Integrated Circuit Systems – FEMTOCLOCKS-TM CRYSTAL-TO-3.3V, 2.5V 125MHZ LVPECL CLOCK GENERATOR

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS843021I-01
FEMTOCLOCKS™ CRYSTAL-TO-3.3V, 2.5V
125MHZ LVPECL CLOCK GENERATOR
APPLICATION SCHEMATIC
Figure 4 shows an example of ICS843021I-01 application
schematic. In this example, the device is operated at
V_CC = 3.3V. The decoupling capacitor should be located as
close as possible to the power pin. The input is driven by a
25MHz quartz crystal. For the LVPECL output drivers, only
two termination examples are shown in this schematic.
Additional termination approaches are shown in the LVPECL
Termination Application Note.
VCC = 3.3V
X1
25MHz
18pF
C2
27pF
C1
27pF
U1
1
2
VCC
3
4
XTAL_OUT
XTAL_IN
VEE
Q0
8
7
nQO
Vcc
OE
6
5
OE
843021I-01
3.3V
R3
133
Zo = 50 Ohm
Zo = 50 Ohm
R4
82.5
R5
133
+
-
R6
82.5
VCC
C3
10uF
C4
.1uF
C5
.1uF
Zo = 50
+
Zo = 50
-
R2
R1
50
50
R3
50
Optional Termination
FIGURE 4. ICS843021I-01 SCHEMATIC EXAMPLE
843021AGI-01
www.icst.com/products/hiperclocks.html
9
REV. A NOVEMBER 30, 2004