ICS85211BI-03 Datasheet, PDF(6/14 Page) Integrated Circuit Systems – LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-LVHSTL FANOUT BUFFER

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ICS85211BI-03 Datasheet, PDF (6/14 Pages) Integrated Circuit Systems – LOW SKEW, 1-TO-2 DIFFERENTIAL-TO-LVHSTL FANOUT BUFFER

◁

Integrated

Circuit

Systems, Inc.

ICS85211BI-03

LOW SKEW, 1-TO-2

DIFFERENTIAL-TO-LVHSTL FANOUT BUFFER

APPLICATION INFORMATION

WIRING THE DIFFERENTIAL INPUT TO ACCEPT SINGLE ENDED LEVELS

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

single ended levels. The reference voltage V_REF = VDD/2 is

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 VDD = 3.3V, V_REF should be 1.25V

and R2/R1 = 0.609.

VDD

Single Ended Clock Input

V_REF

0.1u

CLK

nCLK

FIGURE 1. SINGLE ENDED SIGNAL DRIVING DIFFERENTIAL INPUT

RECOMMENDATIONS FOR UNUSED OUTPUT PINS

OUTPUTS:

LVHSTL OUTPUT

All unused LVHSTL outputs can be left floating. We recommend

that there is no trace attached. Both sides of the differential

output pair should either be left floating or terminated.

85211BMI-03

www.icst.com/products/hiperclocks.html

REV. B NOVEMBER 15, 2005

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