[AP3603]

015000004-E-02

2015/07

- 12 -

■ Recommended Layout

■ GND Layout

GND plane should be as large as possible. The output capacitor and input capacitor should be connected to

the same ground plane.

■ Switching Node Layout

The switching node line between external N-channel MOSFETs, the Schottky barrier diode and power

inductor should be thick and short. Wiring to the DRV1 and DRV2 should be as short as possible.

■ Current Sense Resistor Layout

A current sense resistor should be located as close as possible to the AP3603 so that the wirings to the RSP

pin and the RSN pin from the both ends of the current sense resistor have the same resistance.

■ Feedback Pin Layout

Feedback resistors connected in series between the output capacitor and the GND should be connected as

near as possible to the output capacitor and as far as possible from the switching node. The middle point of

feedback two resistors should be as close as possible to the FB pin.

■ Capacitors for V8, V4 and SS

Capacitors between V8 pin and GND2, V4 pin and GND2, SS pin and GND1 should be connected as near

as possible to the each terminals of the AP3603.

■ Bypass Capacitor

The bypass capacitor between the VDD pin and the GND2 should be connected as near as possible to the

AP3603.

Figure 5. Top Layer Silk

Figure 6. Bottom Layer

Figure 4. Top Layer

Figure 7. Bottom Layer Silk