ICS853052 Datasheet, PDF (7/13 Pages) Integrated Circuit Systems – DUAL LVCMOS / LVTTL-TO-DIFFERENTIAL 2.5V, 3.3V, 5V LVPECL MULTIPLEXER

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS853052
DUAL LVCMOS / LVTTL-TO-DIFFERENTIAL
2.5V, 3.3V, 5V LVPECL MULTIPLEXER
APPLICATION INFORMATION
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 1A and Figure 1B show examples of termination for 2.5V
LVPECL driver. These terminations are equivalent to terminat-
ing 50Ω to V_CC - 2V. For V_CC = 2.5V, the V_CC - 2V is very close to
ground level. The R3 in Figure 1B can be eliminated and the
termination is shown in Figure 1C.
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 1A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
FIGURE 1B. 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 1C. 2.5V LVPECL TERMINATION EXAMPLE
853052AG
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REV. A JULY 1, 2004