1.2MHZ MICROPOWER SYNCHRONOUS STEP-UP CONVERTER

2007-4-19

1/9

FSP3603

APPLICATIONS

Cellular and Smart Phones

Microprocessors and DSP Core Supplies

Wireless and DSL Modems

MP3 Player

Digital Still and Video Cameras

Portable Instruments

PIN CONFIGURATION

(Top View)

Pin Number

Pin Name

Pin Function

1

SW

Power Switch Pin. It is the switch node connection to Inductor.

2

GND

Ground Pin

3

FB

Feedback Input Pin. Connect FB to the center point of the external resistor

divider. The feedback threshold voltage is 1.23V.

4

SHDN

Chip Shutdown Signal Input. Logic high is normal operation mode, Logic

resistor.

5

VOUT

6

VIN

Power Supply Input. Must be closely decoupled to GND, Pin 2, with a 4.7µF

or greater ceramic capacitor.

FEATURES

High Efficiency: Up to 92%

1.2MHz Constant Switching Frequency

Single AA Cell; 3.3V Output Voltage at

Low Start-up Voltage: 0.85V

Integrated main switch and synchronous rectifier. No

Schottky Diode Required

2.5V to 5V Output Voltage Range

Automatic Pulse Skipping Mode Operation

Tiny External Components

<1 µA Shutdown Current

Antiringing Control Reduces EMI

Space Saving 6-Pin Thin SOT23 Package

GENERAL DESCRIPTION

The FSP3603 is a 1.2MHz constant frequency, current

mode PWM step-up converter. It can supply 3.3V

output voltage at 100mA from a single AA Cell. The

device integrates a main switch and a synchronous

rectifier for high efficiency without an external Schottky

diode. A switching frequency of 1.2MHz allows the use

of tiny, low profile inductors and ceramic capacitors.

The current mode PWM operation with internal

compensation provides excellent line and load

transient characteristics. The FSP3603 features Pulse

Skipping Mode operation at light loads to avoid

unacceptable ripple voltage.

The FSP3603 is offered in a low profile (1mm) small

6-Pin SOT23 Package

2

3

6

54

1

SW

GND

FB

VIN

VOUT SHDN