10

FN6415.1

February 13, 2007

PCB Layout Recommendation

The PCB layout is a very important converter design step to

make sure the designed converter works well.

For ISL9105, the power loop is composed of the output

the GND pin. It is necessary to make the power loop as

small as possible and the connecting traces among them

should be direct, short and wide.

The switching node of the converter, the PHASE pin, and the

traces connected to the node are very noisy, so keep the

voltage feedback trace away from these noisy traces.

The input capacitor should be placed to VIN pin as close as

possible. And the ground of input and output capacitors

should be connected as close as possible.

The heat of the IC is mainly dissipated through the thermal

pad. Maximizing the copper area connected to the thermal

pad is preferable. In addition, a solid ground plane is helpful

for better EMI performance.

ISL9105