AP3418

Document number: DS37233 Rev. 3 - 2

2 of 11

www.diodes.com

November 2014

© Diodes Incorporated

AP3418

A Product Line of

Diodes Incorporated

Pin Descriptions

Pin Number

Pin Name

Function

1

EN

Control input pin. Forcing this pin above 1.5V enables the IC. Forcing this

pin below 0.4V shuts down the IC. When the IC is in shutdown mode, all

functions are disabled to decrease the supply current below 1µA

2

GND

Ground pin

3

SW

Power switch output pin. Inductor connection to drain of the internal PFET

and NFET switches

4

VIN

Supply input pin. Bypass to GND with a 4.7µF or greater ceramic

capacitor

5

FB

This is the feedback pin of the device. Connect this pin directly to the

output if the fixed output voltage version is used. For the adjustable

version, an external resistor divider is connected to this pin

Functional Block Diagram

VOLTAGE

REFERENCE

OSCILLATOR

CURRENT

SENSE

ERROR

AMPLIFIER

PWM

COMPARATOR

MAX

CURRENT LIMIT

0.6V

0.4V

LOGIC

CLK

SHORT

CIRCUIT

PROTECTION

REVERSE

COMPARATOR

EN

FB

GND

SW

GND

VIN

VIN

1

5

2

4

3

4

2