REV. 1.0.2 8/26/03

7

PRODUCT SPECIFICATION

FAN2534/FAN2535

General PWB Layout Considerations

For optimum device performance, careful circuit layout and

grounding technics must be used. Establishing a small local

ground, to which the GND pin, and the output and bypass

capacitors are connected, is recommended, while the input

capacitor should be grounded to the main ground plane.

The quiet local ground is then routed back to the main

ground plane using feedthrough vias. In general, the high-

frequency compensation components (input, bypass, and

output capacitors) should be located as close to the device as

possible. The proximity of the output capacitor is especially

important to achieve optimum performance, especially

during high load conditions. A large copper area in the local

ground serves as heat sink (as discussed above) when high

power dissipation significantly increases device temperature.

Component-side copper provides significantly better thermal

performance. Added feedthrough connecting the device side

ground plane to the back plane further reduces thermal

resistance.