SW

4.7pF

C3

4.7PH

L1

FREQ

7

2

6

4

8

3

1

PGND

SGND

BOOT

EN

FB

D1

3A

5V

RF2

100k

C1

22PF

V

IN

2 Cells

R3

150k

RF1

300k

+

V

DD

LM2623

C2

100PF

tan

t

5

LM2623

www.ti.com

SNVS188G – MAY 2004 – REVISED DECEMBER 2005

LM2623 General Purpose, Gated Oscillator Based, DC/DC Boost Converter

Check for Samples: LM2623

1

FEATURES

DESCRIPTION

The LM2623 is a high efficiency, general purpose,

2

•

Good Efficiency Over a Very Wide Load Range

step-up

DC-DC

switching

regulator

for

battery-

•

Very Low Output Voltage Ripple

powered and low input voltage systems. It accepts an

•

Small, VSSOP-8 Package (Half the Footprint of

input voltage between .8 and 14 volts and converts it

Standard 8 pin SOIC Package)

into a regulated output voltage between 1.24 and 14

volts. Efficiencies up to 90% are achievable with the

•

1.09 mm Package Height

LM2623.

•

Up to 2 MHz Switching Frequency

In order to adapt to a number of applications, the

•

.8V to 14V Operating Voltage

LM2623 allows the designer to vary the output

•

1.1V Start-up Voltage

voltage, the operating frequency (300kHz to 2 MHz)

•

1.24V - 14V Adjustable Output Voltage

and duty cycle (17% to 90%) to optimize the part's

performance. The selected values can be fixed or can

•

Up to 2A Load Current at Low Output Voltages

vary with battery voltage or input to output voltage

•

0.17

Ω Internal MOSFET

ratio. The LM2623 uses a very simple, on/off

•

Up to 90% Regulator Efficiency

regulation mode to produce good efficiency and

stable operation over a wide operating range. It

•

normally regulates by skipping switching cycles when

of Supply)

it reaches the regulation limit (Pulse Frequency

•

<2.5µA Specified Supply Current In Shutdown

Modulation).

•

4mm x 4mm Thermally Enhanced WSON

Note:

Please

read

the

Non-Linear

Effect

and

Package Option

Choosing The Correct C3 Capacitor sub-sections of

the Design Procedure section of this data sheet, so

APPLICATIONS

that any challenges with designing with this part can

be taken into account before a board design/layout is

•

Cameras, Pagers and Cell Phones

finalized.

•

PDAs, Palmtop Computers, GPS Devices

For

Alternative

Solutions,

See

Also:

LM2700,

•

White LED Drive, TFT or Scanned LCDs

LM2622, LM2731, LM2733, and LM2621.

•

Flash Memory Programming

•

Hand-Held Instruments

•

1, 2, 3 or 4 Cell Alkaline Systems

•

1, 2 or 3 Cell Lithium-ion Systems

Typical Application Circuit

1

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2004–2005, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.