ISL59440_07 Datasheet, PDF (11/12 Pages) Intersil Corporation – 400MHz Multiplexing Amplifier

ISL59440
PC Board Layout
The frequency response of this circuit depends greatly on
the care taken in designing the PC board. The following are
recommendations to achieve optimum high frequency
performance from your PC board.
• The use of low inductance components such as chip
resistors and chip capacitors is strongly recommended.
• Match channel-channel analog I/O trace lengths and
layout symmetry. This will minimize propagation delay
mismatches.
• Maximize use of AC de-coupled PCB layers. All signal I/O
lines should be routed over continuous ground planes (i.e.
no split planes or PCB gaps under these lines). Avoid vias
in the signal I/O lines.
• Use proper value and location of termination resistors.
Termination resistors should be as close to the device as
possible.
• When testing use good quality connectors and cables,
matching cable types and keeping cable lengths to a
minimum.
• Minimum of 2 power supply de-coupling capacitors are
recommended (1000pF, 0.01µF) as close to the device as
possible - Avoid vias between the cap and the device
because vias add unwanted inductance. Larger caps can
be farther away. When vias are required in a layout, they
should be routed as far away from the device as possible.
• The NIC pins are placed on both sides of the input pins.
These pins are not internally connected to the die. It is
recommended these pins be tied to ground to minimize
crosstalk.
11
FN6162.2
October 10, 2007