OUTPUT CURRENT (mA)

100

80

60

40

20

0

0.1

1

10

100

1000

LM3691

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SNVS506H – MAY 2008 – REVISED SEPTEMBER 2011

LM3691 High Accuracy, Miniature 1A, Step-Down DC-DC Converter for Portable

Applications

Check for Samples: LM3691

1

FEATURES

DESCRIPTION

The

LM3691

step-down

DC-DC

converter

is

2

•

optimized for powering ultra-low voltage circuits from

•

±1% DC Output Voltage Precision

a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It

•

2.3V

provides up to 1A load current, over an input voltage

range from 2.3V to 5.5V. There are several different

•

4 MHz Switching Frequency

fixed voltage output options available.

•

64

μA (typ.) Quiescent Current in ECO Mode

LM3691 has a mode-control pin that allows the user

•

1A Maximum Load Capability

to select Forced PWM mode or ECO mode that

•

Automatic ECO/PWM Mode Switching

changes modes between gated PWM mode and

•

Mode Pin to Select ECO/Forced PWM Mode

PWM automatically depending on the load. In ECO,

•

1

μH Inductor, 4.7 μF Input Capacitor

under light load conditions. ECO mode extends the

(0603(1608) case size) and 4.7

μF Output

battery life through reduction of the quiescent current

Capacitor (0603(1608) Case Size)

during light load conditions and system standby.

•

Current Overload and Thermal Shutdown

The LM3691 is available in a 6-bump DSBGA

Protections

package.

Only

three

external

surface-mount

•

Only Three Tiny Surface-mount External

components, a 1

μH inductor, a 4.7 μF input

Components Required (Solution Size Less

capacitor and a 4.7

μF output capacitor, are required.

APPLICATIONS

•

Mobile Phones

•

Hand-Held Radios

•

MP3 Players

•

Portable Hard Disk Drives

Typical Application Circuit

Figure 1. Typical Application Circuit

Figure 2. Efficiency vs. Output Current

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 © 2008–2011, 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.