
8430AYI-61
www.icst.com/products/hiperclocks.html
REV. C JUNE 2, 2006
12
Integrated
Circuit
Systems, Inc.
ICS8430I-61
500MHZ, CRYSTAL-TO-3.3V, 2.5V DIFFERENTIAL
LVPECL FREQUENCY SYNTHESIZER
TERMINATION FOR 2.5V LVPECL OUTPUT
Figure 6A and Figure 6B show examples of termination for
2.5V LVPECL driver. These terminations are equivalent to ter-
minating 50
Ω to V
CC - 2V. For VCCO = 2.5V, the VCCO - 2V is very
close to ground level. The R3 in Figure 6B can be eliminated
and the termination is shown in Figure 6C.
FIGURE 6C. 2.5V LVPECL TERMINATION EXAMPLE
R2
50
Zo = 50 Ohm
VCCO=2.5V
R1
50
Zo = 50 Ohm
+
-
2.5V
2,5V LVPECL
Driv er
FIGURE 6B. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
VCCO=2.5V
R1
50
R2
50
Zo = 50 Ohm
R3
18
2,5V LVPECL
Driv er
Zo = 50 Ohm
+
-
2.5V
FIGURE 6A. 2.5V LVPECL DRIVER TERMINATION EXAMPLE
R2
62.5
2.5V
2,5V LVPECL
Driv er
R3
250
Zo = 50 Ohm
R4
62.5
2.5V
+
-
R1
250
VCCO=2.5V