ICS843241I-04 Datasheet, PDF (9/14 Pages) Integrated Device Technology – FEMTOCLOCKS™ CRYSTAL-TO-3.3V, 2.5V LVPECL CLOCK GENERATOR

ICS843241I-04
FEMTOCLOCKS™ CRYSTAL-TO- 3.3V, 2.5V LVPECL CLOCK GENERATOR
PRELIMINARY
TERMINATION FOR 2.5V LVPECL OUTPUTS
Figure 5A and Figure 5B show examples of termination for 2.5V
LVPECL driver. These terminations are equivalent to terminating
50Ω to V - 2V. For V = 2.5V, the V - 2V is very close to ground
CC
CC
CC
level. The R3 in Figure 5B can be eliminated and the termination
is shown in Figure 5C.
VC C=2. 5V
Zo = 50 Ohm
Zo = 50 Ohm
2,5V LVPECL
Driv er
2. 5V
R1
R3
250
250
2.5V
+
-
R2
62. 5
R4
62. 5
VCC=2.5V
Zo = 50 Ohm
Zo = 50 Ohm
2,5V LVPECL
Driv er
2. 5V
+
-
R1
R2
50
50
R3
18
FIGURE 5A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
FIGURE 5B. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
VC C=2. 5V
Zo = 50 Ohm
Zo = 50 Ohm
2,5V LVPECL
Driv er
2.5V
+
-
R1
R2
50
50
FIGURE 5C. 2.5V LVPECL TERMINATION EXAMPLE
IDT^™ / ICS^™ 150MHZ, 3.3V, 2.5V LVPECLCLOCK GENERATOR
9
ICS843241AGI-04 REV. A MAY 1, 2008