LM2734 - Thin SOT23 1A Load Step-Down DC-DC Regulator

LM2734

Thin SOT23 1A Load Step-Down DC-DC Regulator

Overview

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Reliability

Obsolete

Features

• Thin SOT23-6 package

• 3.0V to 20V input voltage range

• 0.8V to 18V output voltage range

• 1A output current

• 550kHz (LM2734Y) and 1.6MHz (LM2734X)
• switching frequencies

• 300mΩ NMOS switch

• 30nA shutdown current

• 0.8V, 2% internal voltage reference

• Internal soft-start

• Current-Mode, PWM operation

• WEBENCH® ™ online design tool

• Thermal shutdown

• LM2734XQ/LM2734YQ are AEC-Q100 Grade 1 qualified and are manufactured on an Automotive Grade Flow

Description
The LM2734 regulator is a monolithic, high frequency, PWM step-down DC/DC converter in a 6-pin Thin SOT23 package. It provides all the active functions to provide local DC/DC conversion with fast transient response and accurate regulation in the smallest possible PCB area.

With a minimum of external components and online design support through WEBENCH® ™, the LM2734 is easy to use. The ability to drive 1A loads with an internal 300mΩ NMOS switch using state-of-the-art 0.5µm BiCMOS technology results in the best power density available. The world class control circuitry allows for on-times as low as 13ns, thus supporting exceptionally high frequency conversion over the entire 3V to 20V input operating range down to the minimum output voltage of 0.8V. Switching frequency is internally set to 550kHz (LM2734Y) or 1.6MHz (LM2734X), allowing the use of extremely small surface mount inductors and chip capacitors. Even though the operating frequencies are very high, efficiencies up to 90% are easy to achieve. External shutdown is included, featuring an ultra-low stand-by current of 30nA. The LM2734 utilizes current-mode control and internal compensation to provide high-performance regulation over a wide range of operating conditions. Additional features include internal soft-start circuitry to reduce inrush current, pulse-by-pulse current limit, thermal shutdown, and output over-voltage protection.

Applications

• Local Point of Load Regulation

• Core Power in HDDs

• Set-Top Boxes

• Battery Powered Devices

• USB Powered Devices

• DSL Modems

• Notebook Computers

• Automotive

LM2734X

3.00 <= V in Lower
V
<= V in Upper
V
<= 20.00

V out 0.80 <= V <= 18.00

I out A <= 1.00

Ambient Temperature °C <= 100

What are WEBENCH® tools?

Also Recommended

LM2651▲ 1.5A Synchronous Buck Regulator

LM27341▲ 1.5A, 2MHz Fsw, Frequency Sync

LM2734Z▲ 3MHz Version

LM2738▲ 1.5A Version

LM5010▲ 1A 80V Switching Reg

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LM2734

Also Recommended

LM2651▲	1.5A Synchronous Buck Regulator
LM27341▲	1.5A, 2MHz Fsw, Frequency Sync
LM2734Z▲	3MHz Version
LM2738▲	1.5A Version
LM5010▲	1A 80V Switching Reg

Typical Application click for larger image

Block Diagram click for larger image

Typical Performance click for larger image

Paramaters / Values	LM2734	LM2651	LM27341	LM2734Z	LM2738	LM5010
Output Current	1000 mA	1500 mA	1500 mA	1000 mA	1500 mA	1000 mA
Input Min Voltage	3 Volt	4 Volt	3 Volt	3 Volt	3 Volt	8 Volt
Input Max Voltage	20 Volt	14 Volt	20 Volt	20 Volt	20 Volt	75 Volt
Output Min	0.8 Volt	3.3, 1.24 Volt	1 Volt	0.8 Volt	0.8 Volt	2.5 Volt
Output Max	18 Volt	3.3, 13 Volt	18 Volt	18 Volt	18 Volt	70 Volt
Frequency Min	1600, 550 kHz	300 kHz	1000 kHz	3000 kHz	364, 1280 kHz	50 kHz
Frequency Max	1600, 550 kHz	300 kHz	2350 kHz	3000 kHz	1920, 676 kHz	1000 kHz
Efficiency (peak)	90, 94 %	97 %	93 %	88 %	94.5, 92 %	91 %
On/Off Pin	Yes	Yes	Yes	Yes	Yes	Yes
Error Flag	No	No	No	No	No	No
SoftStart	Yes	Yes	Yes	Yes	Yes	Yes
Sync Pin	No	No	Yes	No	No	No
Inverting	No	No	No	No	No	Yes
Flyback	No	No	No	No	No	No
RegType	Switching Regulator	Switching Regulator	Switching Regulator	Switching Regulator	Switching Regulator	Switching Regulator
Temperature Min	-40 deg C	-40 deg C	-40 deg C	-40 deg C	-40 deg C	-40 deg C
Temperature Max	125 deg C	125 deg C	125 deg C	125 deg C	125 deg C	125 deg C
Adjustable Output	Yes	Yes, No	Yes	Yes	Yes	Yes
Adj Switch Frequency	No	No	Yes	No	No	Yes
PWM Mode	Current	Current	Current	Current	Current	Constant on-time
Topology	Buck	Synchronous Buck	Non-Synchronous Buck Regulator	Buck	Buck	Buck
Special Features	OVP, internal compensation, 30nA shutdown current, pulse-by-pulse current limit	Max. Iq at shutdown is 20uA over full temp range, 7uA typical	OVP, internal compensation, 70nA shutdown current, pulse-by-pulse current limit	OVP, internal compensation, 30nA shutdown current, pulse-by-pulse current limit		No compensation required, ultra-fast transient response
Step-Down	Yes	Yes	Yes	Yes	Yes	Yes
Multiple Output Capability	No	No	No	No	No	No
Output Voltage	Undefined Volt	3.3 Volt		Undefined Volt		Undefined Volt
Output Range	0.8V to 18V	1.24V to 13V	1.0 - 18V	0.8V to 18V		2.5V to 70V
Switching Frequency	1600, 550 kHz	300 kHz	2000 kHz	3000 kHz	1600, 550 kHz	1000 kHz
Feedback Voltage	Undefined Volt	Undefined Volt	1 Volt	Undefined Volt	0.8 Volt	2.5 Volt
Regulator Family	Undefined	Undefined		Undefined	SIMPLE SWITCHER	Undefined
AEC Q-100 Automotive Grade	1		1	1
Automotive	Yes		Yes	Yes		Undefined
Synchronous Rectification	No	Yes	No	No	No	No

Datasheet
Title Size Date Other
Language

LM2734 Thin SOT23 1A Load Step-Down DC-DC Regulator 486
Kbytes 15-Apr-09 日本語

Featured Application Notes
Title Size Date Other
Language

AN-1350: Application Note 1350 LM2734 Evaluation Board 639
Kbytes 4-Feb-05

AN-1822: Application Note 1822 LMH6733 High Definition Video Transmission Over CAT5 691
Kbytes 14-Jan-09

AN-1408: Application Note 1408 Designing Power Over Ethernet Using LM5070 and DP83865 1072
Kbytes 10-Jan-06 中文

More Application Notes
Title Size Date Other
Language

AN-1973: Application Note 1973 Benefits and Challenges of High-Frequency Regulators 348
Kbytes 25-Jun-09

AN-1280: Application Note 1280 LM2731/LM2733 Evaluation Board 55
Kbytes 18-Apr-03

AN-1658: Application Note 1658 LM2735 BOOST and SEPIC DC-DCRegulator 408
Kbytes 26-Jun-07 日本語
 中文

AN-1837: Application Note 1837 LM2738 Evaluation Board 799
Kbytes 10-Apr-08

AN-1418: Application Note 1418 LM2736 Evaluation Board 858
Kbytes 26-Oct-05 中文

AN-1929: Application Note 1929 LM27342 Demonstration Board 507
Kbytes 20-Nov-08

Part Number(s)
(NSID)

Top View

Availability

Current Reported Stock

Budgetary Pricing

Standard Pack Size

LM2734XQMKE/NOPB

RoHS

TSOT

Full production
Lead Time: 8 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	467

$1.78 each at 1K+ pcs

reel
of
250

LM2734YQMKE/NOPB

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	363

$1.49 each at 1K+ pcs

reel
of
250

LM2734XMK/NOPB

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
DIGIKEY	Worldwide	2192
FUTURE	Worldwide	1100
NEWARK	Americas	743

$1.50 each at 1K+ pcs

reel
of
1000

LM2734XQMK/NOPB

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0

$1.78 each at 1K+ pcs

reel
of
1000

LM2734YQMK/NOPB

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0

$1.49 each at 1K+ pcs

reel
of
1000

LM2734YMK/NOPB
LM2734YMK

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	739
AVNET-EM	Worldwide	1000
DIGIKEY	Worldwide	2036
FARNELL	Europe and Asia	1772
FUTURE	Worldwide	1100
KEIKONG	Asia Pacific	1000
NEWARK	Americas	11
RS COMPONENTS	Worldwide	350

$1.25 each at 1K+ pcs

reel
of
1000

LM2734XQMKX/NOPB

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0

$1.78 each at 1K+ pcs

reel
of
3000

LM2734YQMKX/NOPB

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0

$1.49 each at 1K+ pcs

reel
of
3000

LM2734YMKX/NOPB
LM2734YMKX

RoHS

TSOT

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGIKEY		Worldwide	0

$1.25 each at 1K+ pcs

reel
of
3000

Obsolete Versions

Obsolete Part Alternate Part or Supplier Source Last Time Buy Date

LM2734XMFX
LM2734XMKX
NATIONAL SEMICONDUCTOR
01 Dec 2009

Part Number(s)
(NSID)

Description

Availability

Current Reported Stock

Budgetary Pricing

Standard Pack Size

LM2734X EVAL

Thin SOT23 1A Load Step-Down DC-DC Regulator

Full production

Distributor		Region	Qty
DIGIKEY		Worldwide	0
NATIONAL		Worldwide	137

$38.00 each

Description:

LM2734 Thin SOT-23 1A Load Step-Down DC-DC Regulator

Features:

Thin SOT-23-6 package
3.0V to 20V input voltage range
0.8V to 18V output voltage range
1A output current
550kHz (LM2734Y) and 1.6MHz (LM2736X) switching frequencies
300m ohm NMOS switch
30nA shutdown current
0.8V, 2% internal voltage reference
Internal soft-start
Current-Mode, PWM operation
WEBENCH online design tool

Applications:

Local Point of Load Regulation
Core Power in HDDs
Set-Top Boxes
Battery Powered Devices
USB Powered Devices
DSL Modems
Notebook Computers

Contents:

A fully assembled LM2734X evaluation board
LM2734 datasheet
LM2734 eval board appnote

Part Number(s)
(NSID)

Description

Availability

Current Reported Stock

Budgetary Pricing

Standard Pack Size

LM2734Y EVAL

Thin SOT23 1A Load Step-Down DC-DC Regulator

Full production

Distributor		Region	Qty
DIGIKEY		Worldwide	0
NATIONAL		Worldwide	4

$25.50 each

Description:

LM2734 Thin SOT-23 1A Load Step-Down DC-DC Regulator

Features:

Thin SOT-23-6 package
3.0V to 20V input voltage range
0.8V to 18V output voltage range
1A output current
550kHz (LM2734Y) and 1.6MHz (LM2736X) switching frequencies
300m ohm NMOS switch
30nA shutdown current
0.8V, 2% internal voltage reference
Internal soft-start
Current-Mode, PWM operation
WEBENCH online design tool

Applications:

Local Point of Load Regulation
Core Power in HDDs
Set-Top Boxes
Battery Powered Devices
USB Powered Devices
DSL Modems
Notebook Computers

Contents:

A fully assembled LM2734Y evaluation board
LM2734 datasheet
LM2734 eval board appnote

Part Number(s) (NSID)	Type	Pins	MSL Rating	Peak Reflow	RoHS	CAD Symbols	Models	Package Marking Format
LM2734XQMKE/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SUKB XTT
LM2734YQMKE/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SVCB XTT
LM2734XMK/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SFDB XTT
LM2734XQMK/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SUKB XTT
LM2734YQMK/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SVCB XTT
LM2734YMK/NOPB LM2734YMK	TSOT	6	1 1	260 260	RoHS	Download	N/A	SFEB XTT
LM2734XQMKX/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SUKB XTT
LM2734YQMKX/NOPB	TSOT	6	1	260	RoHS	Download	N/A	SVCB XTT
LM2734YMKX/NOPB LM2734YMKX	TSOT	6	1 1	260 260	RoHS	Download	N/A	SFEB XTT

Design Tools
Title Size Date

Article - Automotive Switching Regulators Get Input-Transient-Voltage Protection

Article - Methods and Features of LED Drivers

Reference Design

RD-143 - Lowest Power 8-bit 3 GSPS Data Acquisition System
RD-179 - High-IF Sub-sampling Receiver Subsystem

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)

LM2734XMK PVIP050 0 9960 0 0 855000 5 242608584

LM2734XQMK PVIP050 0 9960 0 0 855000 5 242608584

LM2734XQMKE PVIP050 0 9960 0 0 855000 5 242608584

LM2734XQMKX PVIP050 0 9960 0 0 855000 5 242608584

LM2734YMK PVIP050 0 9960 0 0 855000 5 242608584

LM2734YMKX PVIP050 0 9960 0 0 855000 5 242608584

LM2734YQMK PVIP050 0 9960 0 0 855000 5 242608584

LM2734YQMKE PVIP050 0 9960 0 0 855000 5 242608584

LM2734YQMKX PVIP050 0 9960 0 0 855000 5 242608584

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

Obsolete Versions

Obsolete Part Alternate Part or Supplier Source Last Time Buy Date

LM2734XMFX
LM2734XMKX
NATIONAL SEMICONDUCTOR
01 Dec 2009

[Information as of 20-Nov-2009]