SC631

12

Applications Information (continued)

PCB Layout Considerations

Poor layout can degrade the performance of the regula-

tor and can be a contributory factor in EMI problems,

ground bounce, thermal issues, and resistive voltage

losses. Poor regulation and instability can result.

The following design rules are recommended:

Place the bucket capacitors as close to the device as

possible and on the same side of the board. Use short

wide copper areas between the capacitor pins and

the device pins.

1.

Place the input and output decoupling capacitors

as close as possible to the device and connect these

capacitors’ground pads together to the ground plane

using multiple vias through a short wide copper

area.

Connect pin 1 directly to the copper area under the

thermal pad.

The thermal pad at the center of the device is not

electrically connected.

Connect this pad to the

ground plane using multiple vias.

Use a ground plane to further reduce noise

interference on sensitive circuit nodes.

2.

3.

4.

5.

EN

SC631

C2+

C2-

C1+

C1-

GND

GND

EN