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 2006 Semtech Corp.

www.semtech.com

SC196A

PRELIMINARY

POWER MANAGEMENT

PCB Layout Considerations

Poor layout can degrade the performance of the DC-DC

converter and can contribute to EMI problems, ground

bounce, and resistive voltage losses. Poor regulation and

instability can result.

A few simple design rules can be implemented to ensure

good layout:

Place the inductor and filter capacitors as close to the

device as possible and use short wide traces between

the power components.

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GND

LX

GND

SC196A

Applications Information (Cont.)

Route the output voltage feedback path away from the

inductor and LX node to minimize noise and magnetic

interference.

Maximize ground metal on the component side to

improvethereturnconnectionandthermaldissipation.

Separation between the LX node and GND should be

maintained to avoid coupling of switching noise to the

ground plane.

Use a ground plane with several vias connecting to

the component side ground to further reduce noise

interference on sensitive circuit nodes.

2.

3.

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