ICS85301 Datasheet, PDF (11/19 Pages) Integrated Circuit Systems – 2:1 DIFFERENTIAL-TO-LVPECL MULTIPLEXER

Integrated
Circuit
Systems, Inc.
ICS85301
2:1
DIFFERENTIAL-TO-LVPECL MULTIPLEXER
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 4A and Figure 4B show examples of termination for
2.5V LVPECL driver. These terminations are equivalent to ter-
minating 50Ω 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.
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
FIGURE 4A. 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
R3
18
FIGURE 4B. 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 4C. 2.5V LVPECL TERMINATION EXAMPLE
85301AK
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11
REV. A JANUARY 16, 2006