ICS853S057I Datasheet, PDF (10/16 Pages) Integrated Device Technology – Maximum input/output frequency

ICS853S057I Data Sheet
4:1, DIFFERENTIAL-TO-3.3V, 2.5V LVPECL/ECL CLOCK DATA MULTIPLEXER
Termination for 2.5V LVPECL Outputs
Figure 4A and Figure 4B 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
50Ω
50Ω
2.5V LVPECL Driver
2.5V
R1
250Ω
R3
250Ω
2.5V
+
–
R2
62.5Ω
R4
62.5Ω
VCC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
+
–
R1
R2
50Ω
50Ω
R3
18Ω
Figure 4A. 2.5V LVPECL Driver Termination Example
Figure 4B. 2.5V LVPECL Driver Termination Example
V_CC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
+
–
R1
R2
50Ω
50Ω
Figure 4C. 2.5V LVPECL Driver Termination Example
ICS853S057AGI REVISION A MAY 16, 2012
10
©2012 Integrated Device Technology, Inc.