IDT / ICS FREQUENCY GENERATOR/JITTER ATTENUATION
13
ICS813076CYI REV. A JULY 8, 2008
ICS813076I
FREQUENCY GENERATOR/JITTER ATTENUATION FOR WIRELESS INFRASTRUCTURE
FIGURE 5C. HIPERCLOCKS CLK/nCLK INPUT
DRIVEN BY A 3.3V LVPECL DRIVER
FIGURE 5B. HIPERCLOCKS CLK/nCLK INPUT
DRIVEN BY A 3.3V LVPECL DRIVER
FIGURE 5D. HIPERCLOCKS CLK/nCLK INPUT
DRIVEN BY A 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, LVHSTL, SSTL, HCSL
and other differential signals. Both V
SWING and VOH must meet the
V
PP and VCMR input requirements. Figures 5A to 5F show interface
examples for the HiPerClockS CLK/nCLK input driven by the most
common driver types. The input interfaces suggested here are
FIGURE 5A. HIPERCLOCKS CLK/nCLK INPUT
DRIVEN BY AN IDT OPEN EMITTER
HIPERCLOCKS LVHSTL DRIVER
examples only. Please consult with the vendor of the driver
component to confirm the driver termination requirements. For
example in Figure 5A, the input termination applies for IDT
HiPerClockS open emitter LVHSTL drivers. If you are using an
LVHSTL 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 5E. HIPERCLOCKS CLK/nCLK INPUT
DRIVEN BY A 3.3V HCSL DRIVER
Zo = 50 Ohm
R1
100
3.3V
LVDS_Driv er
Zo = 50 Ohm
Receiv er
CLK
nCLK
3.3V
HCSL
*R3
33
*R4
33
CLK
nCLK
2.5V
3.3V
Zo = 50
Ω
Zo = 50
Ω
HiPerClockS
Input
R1
50
R2
50
*Optional – R3 and R4 can be 0
Ω
FIGURE 5F. HIPERCLOCKS CLK/nCLK INPUT
DRIVEN BY A 2.5V SSTL DRIVER
CLK
nCLK
HiPerClockS
SSTL
2.5V
Zo = 60
Ω
Zo = 60
Ω
2.5V
3.3V
R1
120
R2
120
R3
120
R4
120