ICS843301I-108 Datasheet, PDF (9/15 Pages) Integrated Device Technology – FEMTOCLOCKS™ CRYSTAL-TO-3.3V, 2.5V LVPECL 75MHZ FREQUENCY SYNTHESIZER W/SSC

ICS843301I-108
FEMTOCLOCKS™ CRYSTAL-TO-3.3V, 2.5V LVPECL FREQUENCY SYNTHESIZER W/SSC
PRELIMINARY
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 6A and Figure 6B 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 6B can be eliminated and the termination
is shown in Figure 6C.
VCC=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 6A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
FIGURE 6B. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
VCC=2.5V
Zo = 50 Ohm
Zo = 50 Ohm
2,5V LVPECL
Driv er
2.5V
+
-
R1
R2
50
50
FIGURE 6C. 2.5V LVPECL TERMINATION EXAMPLE
IDT^™ / ICS^™ 3.3V, 2.5V LVPECL FREQUENCY SYNTHESIZER W/SSC 9
ICS843301BGI-108 REV. A OCTOBER 9, 2007