ICS843101-312 Datasheet, PDF (11/14 Pages) Integrated Circuit Systems – FEMTOCLOCKS™ CRYSTAL-TO-LVPECL 312.5MHZ FREQUENCY MARGINING SYNTHESIZER

ADVANCE INFORMATION
Integrated
ICS843101-312
Circuit
Systems, Inc.
FEMTOCLOCKS™ CRYSTAL-TO-LVPECL
312.5MHZ FREQUENCY MARGINING SYNTHESIZER
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 5A and Figure 5B show examples of termination for
2.5V LVPECL driver. These terminations are equivalent to
terminating 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
VCC=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
VCC=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
843101AG-312
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11
OCTOBER 18, 2005