1

2

5

4

3

VIN

SW

FB

EN

GND

L1: 2.2 µH

10 µF

4.7 µF

LM3673

2.7 V to 5.5 V

1

2

5

4

3

VIN

SW

FB

EN

GND

L1: 2.2 µH

10 µF

4.7 µF

LM3673-

ADJ

2.7 V to 5.5 V

R1

R2

C1

C2

Product

Folder

Sample &

Buy

Technical

Documents

Tools &

Software

Support &

Community

LM3673

SNVS434L – JULY 2006 – REVISED OCTOBER 2015

LM3673 2-MHz, 350-mA Step-Down DC-DC Converter

1 Features

3 Description

The

LM3673

step-down

DC-DC

converter

is

1

•

16-µA Typical Quiescent Current

optimized for powering low voltage circuits from a

•

350-mA Maximum Load Capability

single Li-Ion cell battery and input voltage rails from

•

2-MHz PWM Fixed Switching Frequency (Typical)

2.7 V to 5.5 V. It provides up to 350-mA load current

over the entire input voltage range. There are several

•

Automatic PFM/PWM Mode Switching

different fixed voltage output options available, as

•

Available in Fixed and Adjustable Output Voltages

well as an adjustable output voltage version ranging

•

Internal Synchronous Rectification for High

from 1.1 V to 3.3 V.

Efficiency

The device offers superior features and performance

•

Internal Soft Start

for mobile phones and similar portable systems. The

•

0.01-µA Typical Shutdown Current

LM3673 uses intelligent automatic switching between

pulse width modulation (PWM) and pulse frequency

•

Operates From a Single Li-Ion Cell Battery

modulation (PFM) for better efficiency. During PWM

•

Current Overload and Thermal Shutdown

mode, the device operates at a fixed-frequency of

Protection

2 MHz (typical). Hysteretic PFM mode extends the

•

Only Three Tiny Surface-Mount External

battery life by reducing the quiescent current to 16 µA

Components Required (One Inductor, Two

(typical) during light load and standby operation.

Ceramic Capacitors)

Internal

synchronous

rectification

provides

high

efficiency during PWM mode operation. In shutdown

mode, the device turns off and reduces battery

2 Applications

consumption to 0.01 µA (typical).

•

Mobile Phones

The LM3673 is available in a tiny 5-pin DSBGA

•

PDAs

package. A high switching frequency of 2 MHz

•

MP3 Players

(typical) allows the use of three tiny surface-mount

•

W-LAN

components: an inductor and two ceramic capacitors.

•

Portable Instruments

Device Information(1)

•

Digital Still Cameras

PART NUMBER

PACKAGE

BODY SIZE (MAX)

•

Portable Hard Disk Drives

LM3673

DSBGA (5)

1.413 mm × 1.083 mm

(1) For all available packages, see the orderable addendum at

the end of the data sheet.

Typical Application Circuit for ADJ Version

Typical Application Circuit

1

An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,

intellectual property matters and other important disclaimers. PRODUCTION DATA.