AP65403

Document number: DS37126 Rev. 1 - 2

2 of 15

www.diodes.com

March 2014

© Diodes Incorporated

AP65403

Pin Descriptions

Pin

Name

Pin Number

Function

BS

1

High-Side Gate Drive Boost Input. BS supplies the drive for the high-side N-Channel MOSFET a

0.01µF or greater capacitor from SW to BS to power the high side switch.

IN

2

Power Input. IN supplies the power to the IC, as well as the step-down converter switches. Drive IN

with a 4.75V to 17V power source. Bypass IN to GND with a suitably large capacitor to eliminate noise

on the input to the IC. See Input Capacitor.

SW

3

Power Switching Output. SW is the switching node that supplies power to the output. Connect the

output LC filter from SW to the output load. Note that a capacitor is required from SW to BS to power

the high-side switch.

GND

4

Ground

FB

5

Feedback Input. FB senses the output voltage and regulates it. Drive FB with a resistive voltage

divider connected to it from the output voltage. The feedback threshold is 0.800V. See Setting the

Output Voltage.

COMP

6

Compensation Node. COMP is used to compensate the regulation control loop. Connect a series RC

network from COMP to GND. In some cases, an additional capacitor from COMP to GND is required.

See Compensation Components.

EN

7

Enable Input. EN is a digital input that turns the regulator on or off. Drive EN high to turn on the

regulator; low to turn it off. Attach to IN with a 100k

Ω pull up resistor for automatic startup.

SS

8

Soft-Start Control Input. SS controls the soft-start period. Connect a capacitor from SS to GND to set

the soft-start period. A 0.1µF capacitor sets the soft-start period to 13ms. To disable the soft-start

feature, leave SS floating.

EP

EP

Exposed Pad is connected to ground.

Functional Block Diagram

Figure 2. Functional Block Diagram