MC10E411 Datasheet, PDF (1/6 Pages) ON Semiconductor – 1:9 DIFFERENTIAL ECL/PECL RAMBUS CLOCK BUFFER

MOTOROLA
SEMICONDUCTOR TECHNICAL DATA
1:9 Differential ECL/PECL
RAMBus Clock Buffer
MC10E411
The MC10E411 is a low skew 1-to-9 differential driver, designed with
clock distribution in mind. The MC10E411’s function and performance are
similar to the popular MC10E111, with the added feature of 1.2V output
swings. It accepts one signal input, which can be either differential or
single-ended if the VBB output is used. The signal is fanned out to 9
identical differential outputs.
• 200ps Part-to-Part Skew
• 50ps Output-to-Output Skew
• Differential Design
• VBB Output
• Voltage Compensated Outputs
• VEE Range of –4.5 to –5.5V
• 75kΩ Input Pulldown Resistors
1:9 DIFFERENTIAL
ECL/PECL RAMBUS
CLOCK BUFFER
The output voltage swing of the E411 is larger than a standard ECL
swing. The 1.2V output swings provide a signal which can be AC coupled
into RAMBus compatible input loads. The larger output swings are
produced by lowering the VOL of the device. With the exception of the
lower VOL, the E411 is identical to the MC10E111. Note that the larger
output swings eliminate the possibility of temperature compensated
outputs, thus the E411 is only available in the 10E style of ECL. In
addition, because the VOL is lower than standard ECL, the outputs cannot
be terminated to –2.0V. This datasheet provides a few termination
alternatives.
FN SUFFIX
PLASTIC PACKAGE
CASE 776-02
The E411 is specifically designed, modeled and produced with low
skew as the key goal. Optimal design and layout serve to minimize gate to
gate skew within a device, and empirical modeling is used to determine
process control limits that ensure consistent tpd distributions from lot to
lot. The net result is a dependable, guaranteed low skew device.
To ensure that the tight skew specification is met it is necessary that both sides of the differential output are terminated, even if
only one side is being used. In most applications, all nine differential pairs will be used and therefore terminated. In the case
where fewer than nine pairs are used, it is necessary to terminate at least the output pairs on the same package side as the
pair(s) being used on that side, in order to maintain minimum skew. Failure to do this will result in small degradations of
propagation delay (on the order of 10–20ps) of the output(s) being used which, while not being catastrophic to most designs, will
mean a loss of skew margin.
The MC10E411, as with most other ECL devices, can be operated from a positive VCC supply in PECL mode. This allows the
E411 to be used for high performance clock distribution in +5.0V systems. Designers can take advantage of the E411’s
performance to distribute low skew clocks across the backplane or the board. In a PECL environment, series or Thevenin line
terminations are typically used as they require no additional power supplies. For more information on using PECL, designers
should refer to Motorola Application Note AN1406/D.
11/95
© Motorola, Inc. 1996
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