AP1603

Step-Up DC/DC Converter

This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of

this product. No rights under any patent accompany the sale of the product.

Rev.1.0 Jun. 3, 2004

1/8

Features

-A Guaranteed Start-Up from less than 0.9 V.

-High Efficiency.

-Low Quiescent Current.

-Less Number of External Components needed.

-Low Ripple and Low Noise.

-Space Saving Pb-Free Packages: SOT23-6

Applications

-Pagers.

-Cameras.

-Wireless Microphones.

-Pocket Organizers.

-Battery Backup Suppliers.

-Portable Instruments.

General Description

The AP1603 is a high efficiency step-up DC/DC

converter for applications using 1 to 2 NiMH battery

cells. Only three external components are required

to deliver a fixed output voltage of 3.3V. The

AP1603 starts up from less than 0.9V input with

1mA load. Pulse Frequency Modulation scheme

brings optimized performance for applications with

light output loading and low input voltages. The

output ripple and noise are lower compared with the

circuits operating in PSM mode.

The PFM control circuit operating in 150KHz (max.)

switching

rate

results

in

smaller

passive

components. The space saving SOT23-6 packages

make the AP1603 an ideal choice of DC/DC

converter for space conscious applications, like

pagers,

electronic

cameras,

and

wireless

microphones.

Pin Assignments

1

2

3

74

6

LX

GND

OUT

REF

SOT23-6L

AP1603

5

SHDN

FB

Pin Descriptions

Name

Description

REF

1.2V Reference Voltage. Bypass with a 0.1µF

capacitor.

OUT

Power Output. OUT provides bootstrap power

to the IC.

LX

N-Channel and P-Channel Power MOSFET

Drain

GND Ground

SHDN

shutdown mode. Connect to OUT for normal

operation.

FB

Feedback

Ordering Information

Package

AP1603

X

X

Packing

Blank : Tube

A

: Taping

W: SOT23-6L