ICS853111 Datasheet, PDF (9/13 Pages) Integrated Circuit Systems – LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS853111
LOW SKEW, 1-TO-10
DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 3A and Figure 4B 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 4B can be eliminated and the
termination is shown in Figure 4C.
VCCO=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
VCCO=2.5V
Zo = 50 Ohm
Zo = 50 Ohm
2,5V LVPECL
Driv er
2. 5V
+
-
R1
R2
50
50
R3
18
FIGURE 4A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
FIGURE 4B. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
VCCO=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
8 5 3 111 AY
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REV. D JULY 22, 2003