ICS853111B Datasheet, PDF (11/18 Pages) Integrated Circuit Systems – LOW SKEW, 1-TO-10 DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER

Integrated
Circuit
Systems, Inc.
ICS853111B
LOW SKEW, 1-TO-10
DIFFERENTIAL-TO-2.5V/3.3V LVPECL/ECL FANOUT BUFFER
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 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 5B can be eliminated and the
termination is shown in Figure 5C.
VC CO=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 O=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
VCCO=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
853111BY
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11
REV. A JUNE 16, 2005