85408BG

www.icst.com/products/hiperclocks.html

REV. A APRIL 25, 2005

7

Integrated

Circuit

Systems, Inc.

ICS85408

Figure 1 shows how the differential input can be wired to accept

single ended levels. The reference voltage V_REF = V

generated by the bias resistors R1, R2 and C1. This bias circuit

should be located as close as possible to the input pin. The ratio

of R1 and R2 might need to be adjusted to position the V_REF in

the center of the input voltage swing. For example, if the input

clock swing is only 2.5V and V

and R2/R1 = 0.609.

V_REF

R1

1K

C1

0.1u

R2

1K

Single Ended Clock Input

CLK

nCLK

VDD

A general LVDS interface is shown in

Figure 2. In a 100

Ω differ-

ential transmission line environment, LVDS drivers require a

matched load termination of 100

Ω across near the receiver in-

put. For a multiple LVDS outputs buffer, if only partial outputs

are used, it is recommended to terminate the un-used outputs.

3.3V

3.3V

LVDS_DRIVER

R1

100

HiPerClockS

Zo = 50 Ohm

Zo = 50 Ohm

nCLK

CLK