ICS9DB202
Integrated
Circuit
Systems, Inc.
PCI EXPRESS
™
JITTER
ATTENUATOR
DIFFERENTIAL CLOCK INPUT INTERFACE
The CLK /nCLK accepts LVDS, LVPECL, LVHSTL, SSTL, HCSL here are examples only. Please consult with the vendor of the
and other differential signals.BothVSWING and VOH must meet the driver component to confirm the driver termination requirements.
VPP and VCMR input requirements. Figures 3A to 3D show inter- For example in Figure 3A, the input termination applies for ICS
face examples for the HiPerClockS CLK/nCLK input driven by HiPerClockS LVHSTL drivers. If you are using an LVHSTL driver
the most common driver types.The input interfaces suggested from another vendor, use their termination recommendation.
3.3V
3.3V
3.3V
1.8V
Zo = 50 Ohm
CLK
Zo = 50 Ohm
CLK
Zo = 50 Ohm
nCLK
Zo = 50 Ohm
HiPerClockS
Input
LVPECL
nCLK
HiPerClockS
Input
LVHSTL
R1
50
R2
50
ICS
HiPerClockS
R1
50
R2
50
LVHSTL Driver
R3
50
FIGURE 3A. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
ICS HIPERCLOCKS LVHSTL DRIVER
FIGURE 3B. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
3.3V
3.3V
3.3V
3.3V
Zo = 50 Ohm
3.3V
R3
125
R4
125
LVDS_Driver
Zo = 50 Ohm
Zo = 50 Ohm
CLK
CLK
R1
100
nCLK
Receiv er
nCLK
HiPerClockS
Input
Zo = 50 Ohm
LVPECL
R1
84
R2
84
FIGURE 3C. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
3.3V LVPECL DRIVER
FIGURE 3D. HIPERCLOCKS CLK/NCLK INPUT DRIVEN BY
3.3V LVDS DRIVER
9DB202CG
www.icst.com/products/hiperclocks.html
REV. A OCTOBER 6, 2004
8