1

2

5

4

3

SW

FB

EN

GND

L1: 1.0 PH

10 PF

4.7 PF

LM3679

2.5V to 5.5V

Bill of Materials for Low Profile Solution:

CIN = JMK107BJ475K (Taiyo - Yuden)

COUT = JMK107BJ475K (Taiyo - Yuden) x2

Inductor = LQM21PN1R0MC0 (MuRata)

LM3679

www.ti.com

SNVS510A – SEPTEMBER 2007 – REVISED FEBRUARY 2008

LM3679 3MHz, 350mA Miniature Step-Down DC-DC Converter for Ultra Low Profile

Applications (Height < 0.55mm)

Check for Samples: LM3679

1

FEATURES

APPLICATIONS

2

•

16 µA Typical Quiescent Current

•

Mobile Phones

•

350 mA Maximum Load Capability

•

PDAs

•

3 MHz PWM Fixed Switching Frequency (typ)

•

MP3 Players

•

Automatic PFM/PWM Mode Switching

•

W-LAN

•

Available in 5-Bump DSBGA YZR Package and

•

Portable Instruments

YPD Package

•

Digital Still Cameras

•

Internal Synchronous Rectification for High

•

Portable Hard Disk Drives

Efficiency

•

Internal Soft Start

DESCRIPTION

The

LM3679

step-down

DC-DC

converter

is

•

0.01 µA Typical Shutdown Current

optimized for powering ultra-low voltage circuits from

•

Operates from a Single Li-Ion Cell Battery

a single Li-Ion cell battery and input voltage rails from

•

Current Overload and Thermal Shutdown

2.5V to 5.5V. It provides up to 350mA load current,

Protection

over the entire input voltage range. The LM3679

output voltage can be configured to 1.2V, 1.5V, or

•

Three External Components Required for

1.8V.

Typical Applications

•

Low Profile Solution (0.55mm Max Height,

Includes Four External Components)

TYPICAL APPLICATION CIRCUIT

Figure 1. Typical Low Profile Application Circuit

(0.55mm max height using LM3679UR)

1.8V)

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 © 2007–2008, 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.