843751 Datasheet, PDF (11/17 Pages) Integrated Device Technology – FemtoClock™ SAS/SATA Clock Generator

843751 Data Sheet
FEMTOCLOCK™ SAS/SATA CLOCK GENERATOR
Termination for 2.5V LVPECL Outputs
Figure 4A and Figure 5B show examples of termination for 2.5V
LVPECL driver. These terminations are equivalent to terminating 50
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
VCC = 2.5V
50Ω
50Ω
2.5V LVPECL Driver
2.5V
+
–
R1
R2
50Ω
50Ω
Figure 4C. 2.5V LVPECL Driver Termination Example
843751 REVISION B 08.21.15
11
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