ICS853058 Datasheet, PDF (8/15 Pages) Integrated Circuit Systems – 8:1, DIFFERENTIAL-TO-3.3V OR 2.5V LVPECL/ECL CLOCK MULTIPLEXER

Integrated
Circuit
Systems, Inc.
PRELIMINARY
ICS853058
8:1, DIFFERENTIAL-TO-
3.3V OR 2.5V LVPECL/ECL CLOCK MULTIPLEXER
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 3A and Figure 3B 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 3B can be eliminated and the
termination is shown in Figure 3C.
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 3A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
FIGURE 3B. 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 3C. 2.5V LVPECL TERMINATION EXAMPLE
853058AG
www.icst.com/products/hiperclocks.html
8
REV. A APRIL 13, 2004