PCB Layout Check List

When laying out the printed circuit board, the following checklist should be used to ensure proper

operation of the PAM2308. These items are also illustrated graphically in Figure 1. Check the following in

your layout:

1.

The power traces, consisting of the GND trace, the SW trace and the VIN trace should be kept short,

direct and wide.

2.

Does the FB pin connect directly to the feedback resistors? The resistive divider R1/R2 must be con-

nected between the (+) plate of C

and ground.

3.

Does the (+) plate of CIN connect to VIN as closely as possible? This capacitor provides the AC

current to the internal power MOSFETs.

4.

Keep the switching node, SW, away from the sensitive FB node.

5.

Keep the (–) plates of C and C

as close as possible.

Top

Bottom

OUT

IN

OUT

Figure 1 :PAM2308 Suggested Layout

13

,

Power Analog Microelectronics Inc

www.poweranalog.com

PAM2308

Dual High-Efficiency PWM Step-Down DC-DC Coverter

07/2008 Rev 1.0