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SI53302 Datasheet, PDF (18/34 Pages) Silicon Laboratories – 1:10 LOW JITTER UNIVERSAL BUFFER/LEVEL TRANSLATOR WITH 2:1 INPUT MUX
Si53302
2.11. Output Clock Termination Options
The recommended output clock termination options are shown below.
VDDO
DC Coupled LVPECL Termination Scheme 1
R1
R1
VDDO = 3.3V or 2.5V
Si533xx
Q
50
Qn
50
3.3V LVPECL: R1 = 127 Ohm, R2 = 82.5 Ohm
2.5V LVPECL: R1 = 250 Ohm, R2 = 62.5 Ohm
R2
R2
VDD = VDDO
LVPECL
Receiver
VTERM = VDDO – 2V
R1 // R2 = 50 Ohm
DC Coupled LVPECL Termination Scheme 2
VDDO = 3.3V or 2.5V
Si533xx
Q
50
Qn
50
50
VDD = VDDO
LVPECL
Receiver
50
VTERM = VDDO – 2V
VDDO
AC Coupled LVPECL Termination Scheme 1
VDDO = 3.3V or 2.5V
Si533xx
Q
Qn
Rb Rb
R1
0.1 uF
50
50
0.1 uF
R2
R1
VDD = 3.3V or 2.5V
LVPECL
Receiver
R2
VBIAS = VDD – 1.3V
R1 // R2 = 50 Ohm
3.3V LVPECL: R1 = 82.5 Ohm, R2 = 127 Ohm, Rb = 120 Ohm
2.5V LVPECL: R1 = 62.5 Ohm, R2 = 250 Ohm, Rb = 90 Ohm
AC Coupled LVPECL Termination Scheme 2
VDDO = 3.3V or 2.5V
Si533xx
Q
Qn
Rb Rb
0.1 uF
50
50
0.1 uF 50
VDD = 3.3V or 2.5V
LVPECL
Receiver
50
VBIAS = VDD – 1.3 V
3.3V LVPECL: Rb = 120 Ohm
2.5V LVPECL: Rb = 90 Ohm
Figure 8. LVPECL Output Termination
18
Rev. 1.1