843022I-02 Datasheet, PDF (10/17 Pages) Integrated Device Technology – FemtoClock® Crystal-to-3.3V, 2.5V LVPECL Clock Generator

843022I-02 DATA SHEET
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.
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 5A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
FIGURE 5B. 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 5C. 2.5V LVPECL TERMINATION EXAMPLE
FEMTOCLOCKS™ CRYSTAL-TO-3.3V, 2.5V
10
LVPECL CLOCK GENERATOR
REVISION A 11/4/15