ICS843002I-41 Datasheet, PDF (15/23 Pages) Integrated Circuit Systems – 700MHz, FEMTOCLOCKS-TM VCXO BASED SONET/SDH JITTER ATTENUATOR

ICS843002I-41
700MHZ, FEMTOCLOCKS™ VCXO BASED SONET/SDH JITTER ATTENUATOR
Termination for 2.5V LVPECL Outputs
Figure 6A and Figure 6B show examples of termination for 2.5V
LVPECL driver. These terminations are equivalent to terminating
50Ω to V_CCO – 2V. For V_CCO = 2.5V, the V_CCO – 2V is very close to
ground level. The R3 in Figure 6B can be eliminated and the
termination is shown in Figure 6C.
V_CC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
R1
R3
250
250
2.5V
+
–
R2
R4
62.5
62.5
V_CC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
+
–
R1
R2
50
50
R3
18
Figure 6A. 2.5V LVPECL Driver Termination Example
Figure 6B. 2.5V LVPECL Driver Termination Example
VCC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
+
–
R1
R2
50
50
Figure 6C. 2.5V LVPECL Driver Termination Example
IDT™ / ICS™ VCXO BASED SONET/SDH JITTER ATTENUATOR
15
ICS843002AKI-41 REV. A OCTOBER 25, 2007