LM2673 - 3A Step-Down Voltage Regulator with Adjustable Current Limit

LM2673	3A Step-Down Voltage Regulator with Adjustable Current Limit

Overview

Diagrams

Parametrics

Documents

Order

Boards

Packaging

Tools

Reliability

Obsolete Versions

Features

Efficiency up to 94%

Simple and easy to design with (using off-the-shelf external components)

Resistor programmable peak current limit over a range of 2A to 5A.

150 mΩ DMOS output switch

3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V ) versions

±2%maximum output tolerance over full line and load conditions

Wide input voltage range: 8V to 40V

260 KHz fixed frequency internal oscillator

Softstart capability

−40 to +125°C operating junction temperature range

Description
The LM2673 series of regulators are monolithic integrated circuits which provide all of the active functions for a step-down (buck) switching regulator capable of driving up to 3A loads with excellent line and load regulation characteristics. High efficiency (>90%) is obtained through the use of a low ON-resistance DMOS power switch. The series consists of fixed output voltages of 3.3V, 5V and 12V and an adjustable output version.

The SIMPLE SWITCHER concept provides for a complete design using a minimum number of external components. A high fixed frequency oscillator (260KHz) allows the use of physically smaller sized components. A family of standard inductors for use with the LM2673 are available from several manufacturers to greatly simplify the design process.

Other features include the ability to reduce the input surge current at power-ON by adding a softstart timing capacitor to gradually turn on the regulator. The LM2673 series also has built in thermal shutdown and resistor programmable current limit of the power MOSFET switch to protect the device and load circuitry under fault conditions. The output voltage is guaranteed to a ±2% tolerance. The clock frequency is controlled to within a ±11% tolerance.

Applications
Simple to design, high efficiency (>90%) step-down switching regulators

Efficient system pre-regulator for linear voltage regulators

Battery chargers

See Layout Guidelines

WEBENCH® LM2673

Min Max Range

VIN – V    8.00 – 40.00V

VOUT V    1.21 – 40.00V

IOUT A    ≤ 3.00A

Ambient Temp °C    ≤ 100°C

Footprint BOM Cost Efficiency

What are WEBENCH® tools?

Also Recommended

LM22673▲ Wider Input Voltage Range (4.5V To 42V), Fixed 500kHz

LM25576▲ Fast-Transient Response

LM5576▲ Up To 75V Vin, 3A Iout

Typical Application click for larger image

Block Diagram click for larger image

Typical Performance *click for larger image

Parameters / Values	LM2673	LM22673	LM25576	LM5576
Output Current	3000 mA	3000 mA	3000 mA	3000 mA
Input Min Voltage	15, 8 Volt	4.5 Volt	6 Volt	6 Volt
Input Max Voltage	40 Volt	42 Volt	42 Volt	75 Volt
Output Min	3.3, 1.23, 12, 5 Volt	1.285 Volt	1.23 Volt	1.23 Volt
Output Max	3.3, 12, 37, 5 Volt		40 Volt	70 Volt
Frequency Min	260 kHz		50 kHz	50 kHz
Frequency Max	260 kHz		1000 kHz	500 kHz
Efficiency (peak)	94, 88, 86 %	92 %	91 %	88 %
On/Off Pin	No	No	Yes	Yes
PowerGood / Error Flag	No	No	No	No
SoftStart	Yes	Yes	Yes	Yes
Sync Pin	No	No	Yes	Yes
Flyback	No	No	No	No
RegType	Switching Regulator	Switching Regulator	Switching Regulator	Switching Regulator
Temperature Min	-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
Adjustable Output	Yes, No	Yes	Yes	Yes
Adj Switch Frequency	No	No	Yes	Yes
PWM Mode	Voltage with Vin Feedforward	Voltage Mode Control	Current	Current
Topology	Buck	Buck	Buck	Buck
Special Features	Programmable current limit, 2% output voltage accuracy, SIMPLE SWITCHER regulator	Adjustable Current Limit	1.5% feedback voltage accuracy, emulated current mode	1.5% feedback voltage accuracy, emulated current mode
Step-Down	Yes	Yes	Yes	Yes
Multiple Output Capability	No	No	No	No
Output Power	Undefined Watt		Undefined Watt	Undefined Watt
Output Voltage	3.3, 12, Undefined, 5 Volt		Undefined Volt	Undefined Volt
Output Range	12V, 1.23V to 37V, 3.3V, 5V		1.23V to 37V	1.23V to 70V
Switching Frequency	260 kHz	500 kHz	1000 kHz	500 kHz
Regulator Family	SIMPLE SWITCHER	SIMPLE SWITCHER	SIMPLE SWITCHER	SIMPLE SWITCHER
Synchronous Rectification	No	No	No	No

Datasheets
Title Size Date Other
Language

LM2673 3A Step-Down Voltage Regulator with Adjustable Current Limit 667
Kbytes 29-Feb-08 日本語

Application Notes
Title Size Date Other
Language

AN-1135: Application Note 1135 LM267X 3A, 5A Evaluation Boards 2433
Kbytes 4-Mar-11

AN-1157: Application Note 1157 Positive to Negative Buck‐Boost Converter Using LM267X Simple Switcher Regulators 189
Kbytes 1-May-04 日本語
 中文

Part Number(s)
(NSID)

Top View

Availability

Current Reported Stock

Budgetary Pricing

Pack
Size

LM2673S-12/NOPB

LM2673S-12

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	66
DIGI-KEY	Worldwide	240
FARNELL	Europe and Asia	356
NEWARK	Americas	124
RS COMPONENTS	Worldwide	14
TAYLOR	Americas	183

$1.98 each at 1K+ pcs

rail
of
45

LM2673S-3.3/NOPB

LM2673S-3.3

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	66
AVNET-EM	Worldwide	545
DIGI-KEY	Worldwide	206
MOUSER	Worldwide	130
NEWARK	Americas	174
RS COMPONENTS	Worldwide	16
TAYLOR	Americas	291

$1.98 each at 1K+ pcs

rail
of
45

LM2673S-5.0/NOPB

LM2673S-5.0

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	1355
AVNET-EM	Worldwide	249
DIGI-KEY	Worldwide	168
MOUSER	Worldwide	225
NEWARK	Americas	95
RS COMPONENTS	Worldwide	50
TAYLOR	Americas	1355

$1.98 each at 1K+ pcs

rail
of
45

LM2673S-ADJ/NOPB

LM2673S-ADJ

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	9
AVNET-EM	Worldwide	70
DIGI-KEY	Worldwide	3664
FARNELL	Europe and Asia	586
MOUSER	Worldwide	523
NEWARK	Americas	259
RS COMPONENTS	Worldwide	69
TAYLOR	Americas	1164

$1.98 each at 1K+ pcs

rail
of
45

LM2673SD-12/NOPB

LM2673SD-12

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGI-KEY		Worldwide	750
MOUSER		Worldwide	250

$1.98 each at 1K+ pcs

reel
of
250

LM2673SD-3.3/NOPB

LM2673SD-3.3

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	500
AVNET-EM	Worldwide	2250
DIGI-KEY	Worldwide	1974
MOUSER	Worldwide	250
TAYLOR	Americas	500

$1.98 each at 1K+ pcs

reel
of
250

LM2673SD-5.0/NOPB

LM2673SD-5.0

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	500
AVNET-EM	Worldwide	250
DIGI-KEY	Worldwide	413
MOUSER	Worldwide	250
NEWARK	Americas	57
TAYLOR	Americas	500

$1.98 each at 1K+ pcs

reel
of
250

LM2673SD-ADJ/NOPB

LM2673SD-ADJ

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	250
AVNET-EM	Worldwide	250
DIGI-KEY	Worldwide	807
FARNELL	Europe and Asia	10
MOUSER	Worldwide	225
NEWARK	Americas	264
TAYLOR	Americas	250

$1.98 each at 1K+ pcs

reel
of
250

LM2673SDX-12

RoHS Status

LLP

Full production
Lead Time: 16 weeks

Distributor		Region	Qty
DIGI-KEY		Worldwide	0

$1.98 each at 1K+ pcs

reel
of
2500

LM2673SDX-3.3/NOPB

LM2673SDX-3.3

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGI-KEY		Worldwide	0

$1.98 each at 1K+ pcs

reel
of
2500

LM2673SDX-5.0/NOPB

LM2673SDX-5.0

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGI-KEY		Worldwide	0

$1.98 each at 1K+ pcs

reel
of
2500

LM2673SDX-ADJ/NOPB

LM2673SDX-ADJ

RoHS Status

LLP

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGI-KEY		Worldwide	0

$1.98 each at 1K+ pcs

reel
of
2500

LM2673SX-12/NOPB

LM2673SX-12

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
AVNET-EM		Worldwide	1000
DIGI-KEY		Worldwide	0

$1.98 each at 1K+ pcs

reel
of
500

LM2673SX-3.3/NOPB

LM2673SX-3.3

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	500
AVNET-EM	Worldwide	1000
DIGI-KEY	Worldwide	0
MOUSER	Worldwide	500
TAYLOR	Americas	500

$1.98 each at 1K+ pcs

reel
of
500

LM2673SX-5.0/NOPB

LM2673SX-5.0

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	1500
AVNET-EM	Worldwide	500
DIGI-KEY	Worldwide	0
MOUSER	Worldwide	500
TAYLOR	Americas	1500

$1.98 each at 1K+ pcs

reel
of
500

LM2673SX-ADJ/NOPB

LM2673SX-ADJ

RoHS Status

TO-263

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	1500
AVNET-EM	Worldwide	2000
DIGI-KEY	Worldwide	0
MOUSER	Worldwide	123
TAYLOR	Americas	7050

$1.98 each at 1K+ pcs

reel
of
500

LM2673T-12/NOPB

LM2673T-12

RoHS Status

TO-220

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
DIGI-KEY	Worldwide	173
FARNELL	Europe and Asia	15
MOUSER	Worldwide	180

$1.98 each at 1K+ pcs

rail
of
45

LM2673T-3.3/NOPB

LM2673T-3.3

RoHS Status

TO-220

Full production
Lead Time: 6 weeks

Distributor		Region	Qty
DIGI-KEY		Worldwide	197
MOUSER		Worldwide	180

$1.98 each at 1K+ pcs

rail
of
45

LM2673T-5.0/NOPB

LM2673T-5.0

RoHS Status

TO-220

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	125
DIGI-KEY	Worldwide	272
MOUSER	Worldwide	175
NEWARK	Americas	177
RS COMPONENTS	Worldwide	2
TAYLOR	Americas	265

$1.98 each at 1K+ pcs

rail
of
45

LM2673T-ADJ/NOPB

LM2673T-ADJ

RoHS Status

TO-220

Full production
Lead Time: 6 weeks

Distributor	Region	Qty
ARROW	Worldwide	95
DIGI-KEY	Worldwide	215
FARNELL	Europe and Asia	72
MOUSER	Worldwide	165
RS COMPONENTS	Worldwide	21
TAYLOR	Americas	95
TECHMOSA	Asia Pacific	360

$1.98 each at 1K+ pcs

rail
of
45

Obsolete Versions

Obsolete Part Alternate Part or Supplier Source Last Time Buy Date

LM2673LD-12
NONE
NONE
30 Jan 2004

LM2673LD-3.3
NONE
NONE
30 Jan 2004

LM2673LD-5.0
NONE
NONE
30 Jan 2004

LM2673LD-ADJ
NONE
NONE
30 Jan 2004

LM2673LDX-12
NONE
NONE
30 Jan 2004

LM2673LDX-3.3
NONE
NONE
30 Jan 2004

LM2673LDX-5.0
NONE
NONE
30 Jan 2004

LM2673LDX-ADJ
NONE
NONE
30 Jan 2004

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM2673.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM2673 is located at RoHS Status.

Part Number(s)
(NSID)

Description

Availability

Current Reported Stock

Budgetary Pricing

Pack
Size

LM2673-5.0EVAL

SIMPLE SWITCHER^® 3A Step-Down Voltage Regulator with Adjustable Current Limit

Full production

Distributor		Region	Qty
DIGI-KEY		Worldwide	0
MOUSER		Worldwide	2

$30.00 each

Description:

Simple Switcher 3A Step-Down Voltage Regulatory with Adjustable Current Limit

Features:

Efficiency up to 94%
Simple and easy to design with (using off-the -shelf external components)
Resistor programmable peak current limit over a range of 2A to 5A
150 m ohm DMOS output switch
3.3V, 5V and 12V fixed output and adjustable (1.2V to 37V) versions
+/-2% maximum output tolerance over full line and load conditions
Wide input voltage range: 8V to 40V
260 KHz fixed frequency internal oscillator
Softstart capability
-40 to +125 degrees C operating junction temperature range

Contents:

A fully assembled step-down DC/DC converter demonstration board using LM2673S-5.0
Power Manangement CD
Datasheets
Simple Switcher® selection guide
Evaluation board Application Note

National Semiconductor follows the provisions of the Product Stewardship Guide for Customers (CSP-9-111C1) and Banned Substances and Materials of Interest Specification (CSP-9-111S2) for regulatory environmental compliance. Details may be found at: www.national.com/en/packaging/greennopb.html. Lead free products are RoHS compliant.

Lead Free product status is available through the search tool located here

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM2673S-12/NOPB LM2673S-12	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-12
LM2673S-3.3/NOPB LM2673S-3.3	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-3.3
LM2673S-5.0/NOPB LM2673S-5.0	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-5.0
LM2673S-ADJ/NOPB LM2673S-ADJ	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-ADJ
LM2673SD-12/NOPB LM2673SD-12	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002SB
LM2673SD-3.3/NOPB LM2673SD-3.3	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002TB
LM2673SD-5.0/NOPB LM2673SD-5.0	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002UB
LM2673SD-ADJ/NOPB LM2673SD-ADJ	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002VB
LM2673SDX-12	94.76	LLP	14	1	260	Detail	Download	N/A	NS UZXYTT S0002SB
LM2673SDX-3.3/NOPB LM2673SDX-3.3	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002TB
LM2673SDX-5.0/NOPB LM2673SDX-5.0	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002UB
LM2673SDX-ADJ/NOPB LM2673SDX-ADJ	94.439 94.76	LLP	14	1 1	260 260	Detail	Download	N/A	NS UZXYTT S0002VB
LM2673SX-12/NOPB LM2673SX-12	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-12
LM2673SX-3.3/NOPB LM2673SX-3.3	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-3.3
LM2673SX-5.0/NOPB LM2673SX-5.0	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-5.0
LM2673SX-ADJ/NOPB LM2673SX-ADJ	1608.332 1609.822	TO-263	7	3 3	245 235	Detail	Download	N/A	NSUZXYTTE# LM2673 S-ADJ
LM2673T-12/NOPB LM2673T-12	1846.782 1858.793	TO-220	7	1 1	NA NA	Detail	Download	N/A	NSUZXYTTE# LM2673 T-12
LM2673T-3.3/NOPB LM2673T-3.3	1846.782 1858.793	TO-220	7	1 1	NA NA	Detail	Download	N/A	NSUZXYTTE# LM2673 T-3.3
LM2673T-5.0/NOPB LM2673T-5.0	1846.782 1858.793	TO-220	7	1 1	NA NA	Detail	Download	N/A	NSUZXYTTE# LM2673 T-5.0
LM2673T-ADJ/NOPB LM2673T-ADJ	1846.782 1858.793	TO-220	7	1 1	NA NA	Detail	Download	N/A	NSUZXYTTE# LM2673 T-ADJ

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM2673.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM2673 is located at RoHS Status.

CAD Symbols and Models
Download LM2673 CAD Symbols

Models
N/A

Reliability Metrics

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

LM2673S-12 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673S-3.3 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673S-5.0 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673S-ADJ LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SD-12 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SD-3.3 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SD-5.0 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SD-ADJ LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SDX-12 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SDX-3.3 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SDX-5.0 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SDX-ADJ LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SX-12 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SX-3.3 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SX-5.0 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673SX-ADJ LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673T-12 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673T-3.3 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673T-5.0 LMDMOS 0 18295 0 0 2650000 2 751944735

LM2673T-ADJ LMDMOS 0 18295 0 0 2650000 2 751944735

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.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM2673.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM2673 is located at RoHS Status.

[Information as of 9-Feb-2012]

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