ICS853S024AY REVISION A JULY 20, 2011

12

©2011 Integrated Device Technology, Inc.

ICS853S024 Data Sheet

LOW SKEW, 1-TO-24, DIFFERENTIAL-TO-3.3V, 2.5V LVPECL 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 50

Ω

to VCC – 2V. For VCC = 2.5V, the VCC – 2V is very close to ground

level. The R3 in Figure 5B can be eliminated and the termination is

shown in Figure 5C.

Figure 5A. 2.5V LVPECL Driver Termination Example

Figure 5C. 2.5V LVPECL Driver Termination Example

Figure 5B. 2.5V LVPECL Driver Termination Example

2.5V LVPECL Driver

VCC = 2.5V

2.5V

2.5V

50

Ω

50

Ω

R1

250

Ω

R3

250

Ω

R2

62.5

Ω

R4

62.5

Ω

+

–

2.5V LVPECL Driver

VCC = 2.5V

2.5V

50

Ω

50

Ω

R1

50

Ω

R2

50

Ω

+

–

2.5V LVPECL Driver

VCC = 2.5V

2.5V

50

Ω

50

Ω

R1

50

Ω

R2

50

Ω

R3

18

Ω

+

–