Datasheet

AD8106/AD8107
Rev. 0 | Page 20 of 28
Each output is separated from its two neighboring outputs by an
analog ground pin and an analog supply pin of one polarity or
the other. Each of these analog supply pins provides power to
the output stages for only the two nearest outputs. These supply
pins and analog grounds provide shielding, physical separation,
and a low impedance supply for the outputs. Individual
bypassing of these supply pins with a 0.01 μF chip capacitor
directly to the ground plane minimizes high frequency output
crosstalk via the mechanism of sharing common impedances.
Each output also has an on-chip compensation capacitor that is
individually tied to the nearby analog ground pins AGND00
through AGND03. This technique reduces crosstalk by preventing
the currents that flow in these paths from sharing a common
impedance on the IC and in the package pins. These AGNDxx
signals should all be connected directly to the ground plane.
The input and output signals have minimum crosstalk if they
are located between ground planes on layers above and below,
and separated by ground in between. Vias should be located as
close to the IC as possible to carry the inputs and outputs to the
inner layer. The only place the input and output signals surface
is at the input termination resistors and the output series back
termination resistors. These signals should also be separated, to
the largest extent possible, as soon as they emerge from the IC
package.