AP3403

Document number: DS36839 Rev. 3 - 2

2 of 9

www.diodes.com

May 2015

© Diodes Incorporated

AP3403

A Product Line of

Diodes Incorporated

Pin Descriptions

Pin Number

Pin Name

Function

1

EN

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

on. Drive low to turn the regulator off.

2

AGND

Signal Ground Pin

3

PGND

Power Ground Pin

4

SW

Power switch output pin. This pin is connected to the inductor.

5

VIN

Supply power input pin. A capacitor should be connected between VIN pin and GND - to keep the input

voltage constant.

6

FB

Feedback pin. This pin is connected to an external resistor divider to program the system output voltage.

Functional Block Diagram

1

6

3

4

SW

PGND

Error

Amplifier

FB

EN

PWM

Comparator

Buffer &

Dead Time

Control

Logic

Control

Logic

Current

Sensing

Reverse Inductor

Current Comparator

Vin OVP Comparator

Oscillator

Slope

Compensation

OCP

Comparator

Soft

Start

Bias

Generator

Shutdown

Comparator

Bandgap

Reference

UVLO

5

VIN

2

AGND