
85210AY-31
www.idt.com
REV. C JULY 10, 2012
8
ICS85210-31
LOW SKEW, DUAL, 1-TO-5
DIFFERENTIAL-TO-HSTL FANOUT BUFFER
FIGURE 3C. CLK/nCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 3B. CLK/nCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 3D. CLK/nCLK INPUT DRIVEN BY
3.3V LVDS DRIVER
3.3V
R1
50
R3
50
Zo = 50 Ohm
LVPECL
Zo = 50 Ohm
HiPerClockS
CLK
nCLK
3.3V
Input
R2
50
Zo = 50 Ohm
Input
HiPerClockS
CLK
nCLK
3.3V
R3
125
R2
84
Zo = 50 Ohm
3.3V
R4
125
LVPECL
R1
84
3.3V
DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, HSTL, SSTL, HCSL
and other differential signals. Both V
SWING and VOH must meet the
V
PP and VCMR input requirements.
Figures 3A to 3E show
interface examples for the CLK/nCLK input driven by the most
common driver types. The input interfaces suggested here
FIGURE 3A. CLK/nCLK INPUT DRIVEN BY
HSTL DRIVER
are examples only. Please consult with the vendor of the driver
component to confirm the driver termination requirements. For
example in
Figure 3A, the input termination applies for HSTL
drivers. If you are using an HSTL driver from another vendor,
use their termination recommendation.
1.8V
R2
50
Input
LVHSTL Driver
ICS
HiPerClockS
R1
50
LVHSTL
3.3V
Zo = 50 Ohm
HiPerClockS
CLK
nCLK
FIGURE 3E. CLK/nCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER WITH AC COUPLE
Zo = 50 Ohm
R3
125
HiPerClockS
CLK
nCLK
3.3V
R5
100 - 200
3.3V
R2
84
3.3V
R6
100 - 200
Input
R5,R6 locate near the driver pin.
Zo = 50 Ohm
R1
84
R4
125
C2
LVPECL
C1
Zo = 50 Ohm
R1
100
3.3V
LVDS_Driv er
Zo = 50 Ohm
Receiv er
CLK
nCLK
3.3V