
843081AGI-01
www.icst.com/products/hiperclocks.html
REV. B JANUARY 23, 2006
9
Integrated
Circuit
Systems, Inc.
ICS843081I-01
F
EMTO
C
LOCKS
C
RYSTAL
-
TO
-
3.3V, 2.5V LVPECL C
LOCK
M
ULTIPLIER
T
ERMINATION
FOR
2.5V LVPECL O
UTPUT
Figure 4A
and
Figure 4B
show examples of termination for 2.5V
LVPECL driver. These terminations are equivalent to terminat-
ing 50
Ω
to V
CC
- 2V. For V
CC
= 2.5V, the V
CC
- 2V is very close to
ground level. The R3 in Figure 4B can be eliminated and the
termination is shown in
Figure 4C.
F
IGURE
4C. 2.5V LVPECL T
ERMINATION
E
XAMPLE
F
IGURE
4B. 2.5V LVPECL D
RIVER
T
ERMINATION
E
XAMPLE
F
IGURE
4A. 2.5V LVPECL D
RIVER
T
ERMINATION
E
XAMPLE
R2
62.5
Zo = 50 Ohm
R1
250
+
-
2.5V
2,5V LVPECL
Driver
R4
62.5
R3
250
Zo = 50 Ohm
2.5V
VCC=2.5V
R1
50
R3
18
Zo = 50 Ohm
Zo = 50 Ohm
+
-
2,5V LVPECL
Driver
VCC=2.5V
2.5V
R2
50
2,5V LVPECL
Driver
VCC=2.5V
R1
50
R2
50
2.5V
Zo = 50 Ohm
Zo = 50 Ohm
+
-