AP1605

PWM/PFM DUAL-MODE STEP-DOWN SWITCHING

REGULATOR

AP1605 Rev. 1

5 of 7

JANUARY 2007

www.diodes.com

Test Circuit

A

FB

Vcc

Vss

open

open

FB

Vcc

Vss

+

-

SW

SW

PVcc

PVcc

A

FB

Vcc

Vss

+

-

V

SW

PVcc

CE

CE

CE

Vcc

Vcc

Vcc

Enable function test

Feedback function test

Operating function test

10uH

+

-

100uF

100uF

100uF

Function Description

PWM/PFM Control (AP1605 Series)

The AP1605 consists of DC/DC converters that employ a PWM/PFM auto-switch system.

In converters of the AP1605, the PFM mode varies in a range of duty cycle from 0% to 25%, and the PWM mode varies in a range of duty

cycle from 25% to 100% according to the load current, and yet ripple voltage produced by the switching can easily be removed through a

filter because the switching frequency remains constant. Therefore, these converters provide a low-ripple power over broad ranges of

input voltage and load current.