Efficiency vs Load Current

LOAD CURRENT (mA)

3.3 -5V Boost

^z_ s Υ]}v

0

200

400

600

800

70

80

90

100

LM2731

³<´

SW

FB

GND

SHDN

U1

R3

51K

SHDN

GND

C1

2.2PF

R2

13.3K

CF

470pF

D1

MBR0520

R1/40.5K

L1/6.8PH

C2

22PF

5V

OUT

700mA

(TYP)

Efficiency vs Load Current

LOAD CURRENT (mA)

0 100

200

300 400

70

80

90

100

LM2731

³;´

SW

FB

GND

SHDN

U1

R3

51K

SHDN

GND

C1

2.2PF

R2

13.3K

CF

220pF

D1

MBR0520

R1/117K

L1/10PH

C2

4.7PF

12V

OUT

500mA

(TYP)

500

5 - 12V Boost

^y_ s Υ]}v

TI Confidential - NDA Restrictions

LM2731

www.ti.com

SNVS217F – MAY 2004 – REVISED NOVEMBER 2012

LM2731 0.6/1.6 MHz Boost Converters With 22V Internal FET Switch in SOT-23

Check for Samples: LM2731

1

FEATURES

DESCRIPTION

The LM2731 switching regulators are current-mode

2

•

22V DMOS FET Switch

boost converters operating at fixed frequencies of 1.6

•

1.6 MHz (“X”), 0.6 MHz (“Y”) Switching

MHz (“X” option) and 600 kHz (“Y” option).

Frequency

The use of SOT-23 package, made possible by the

•

minimal power loss of the internal 1.8A switch, and

•

Switch Current up to 1.8A

use of small inductors and capacitors result in the

industry's highest power density. The 22V internal

•

Wide Input Voltage Range (2.7V–14V)

switch makes these solutions perfect for boosting to

•

Low Shutdown Current (<1 µA)

voltages up to 20V.

•

5-Lead SOT-23 Package

These parts have a logic-level shutdown pin that can

•

Uses Tiny Capacitors and Inductors

be used to reduce quiescent current and extend

•

Cycle-by-Cycle Current Limiting

battery life.

•

Internally Compensated

Protection is provided through cycle-by-cycle current

limiting and thermal shutdown. Internal compensation

APPLICATIONS

simplifies design and reduces component count.

•

White LED Current Source

Table 1. Switch Frequency

•

PDA’s and Palm-Top Computers

X

Y

•

Digital Cameras

1.6 MHz

0.6 MHz

•

Portable Phones and Games

•

Local Boost Regulator

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 © 2004–2012, 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.