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 2004 Semtech Corp.

www.semtech.com

SC338(A)

PRELIMINARY

POWER MANAGEMENT

Applications Infomation (Cont.)

need to be located right next to the power devices. Thus

very accurate output voltages can be obtained since

changes due to heating effects will be minimal.

The 0.1µF bypass capacitor should be located close to

the supply (IN) and GND pins, and connected directly to

the ground plane.

The feedback resistors should be located at the device,

with the sense line from the output routed from the load

(or top end of the droop resistor if passive droop is being

used) directly to the feedback chain. If passive droop is

being used, the droop resistor should be located right at

the load to avoid adding additional unplanned droop.

Sense and drive lines should be routed away from noisy

traces or components.

For very low input to output voltage differentials, the

input to output / load path should be as wide and short

as possible. Where greater headroom is available, wide

traces may suffice.

Power dissipation within the device is practically

negligible, thus requiring no special consideration during

layout. The MOSFET pass devices should be laid out

according to the manufacturer’s guidelines for the power

being dissipated within them.