ICS853014 Datasheet, PDF (12/19 Pages) Integrated Circuit Systems – LOW SKEW, 1-TO-5 2.5V/3.3V DIFFERENTIAL-TO-LVPECL/ECL FANOUT BUFFER

ICS853014
LOW SKEW, 1-TO-5, DIFFERENTIAL-TO-2.5V, 3.3V LVPECL/ECL FANOUT BUFFER
Termination for 2.5V LVPECL Outputs
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 5B can be eliminated and the
termination is shown in Figure 5C.
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 5A. 2.5V LVPECL Driver Termination Example
Figure 5B. 2.5V LVPECL Driver Termination Example
VCC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
+
–
R1
R2
50
50
Figure 5C. 2.5V LVPECL Driver Termination Example
IDT™ / ICS™ 2.5V, 3.3V LVPECL/ECL FANOUT BUFFER
12
ICS853014BG REV. DNOVEMBER 12, 2007