© Semiconductor Components Industries, LLC, 2002

August, 2002 – Rev. 5

1

Publication Order Number:

MC100EP809/D

MC100EP809

3.3V1:9 Differential

HSTL/PECL to HSTL Clock

Driver with LVTTL Clock

Select and Enable

The MC100EP809 is a low skew 1–to–9 differential clock driver,

designed with clock distribution in mind, accepting two clock sources into

an input multiplexer. The part is designed for use in low voltage

applications which require a large number of outputs to drive precisely

aligned low skew signals to their destination. The two clock inputs are

differential HSTL or PECL and they are selected by the CLK_SEL pin

which is LVTTL. To avoid generation of a runt clock pulse when the

device is enabled/disabled, the Output Enable (OE), which is LVTTL, is

synchronous ensuring the outputs will only be enabled/disabled when they

are already in LOW state (See Figure 8).

The MC100EP809 guarantees low output–to–output skew. The optimal

design, layout, and processing minimize skew within a device and from lot

to lot. The MC100EP809 output structure uses open emitter architecture

and will be terminated with 50

W to ground instead of a standard HSTL

configuration (See Figure 6). To ensure the tight skew specification is

realized, both sides of the differential output need to be terminated

identically into 50

W even if only one output is being used. If an output pair

is unused, both outputs may be left open (unterminated) without affecting

skew.

Designers can take advantage of the EP809’s performance to

distribute low skew clocks across the backplane of the board. HSTL

clock inputs may be driven single–end by biasing the non–driven pin

in an input pair (see Figure 7).

Voltage

32

1

MC100

AWLYYWW

EP809

32–LEAD LQFP

FA SUFFIX

CASE 873A

Device

Package

Shipping

ORDERING INFORMATION

MC100EP809FA

LQFP–32

250 Units/Tray

MC100EP809FAR2

LQFP–32

2000/Tape & Reel

MARKING

DIAGRAM*

A

= Assembly Location

WL = Wafer Lot

YY = Year

WW = Work Week

*For additional information, see Application Note

AND8002/D

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