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  • The L4971 is a step down monolithic power switching regulator delivering 1.5A at a voltage between 3.3V and 50V (selected by a simple external divider). Realized in BCD mixed technology, the device uses an internal power D-MOS transistor (with a typical Rdson of 0.25Ω) to obtain very high efficency and high switching speed.

    A switching frequency up to 300KHz is achievable (the maximum power dissipation of the packages must be observed).
    A wide input voltage range between 8V to 55V and output voltages regulated from 3.3V to 50V cover the majority of today’s applications.
    Features of this new generations of DC-DC converter include pulse-by-pulse current limit, hiccup mode for short circuit protection, voltage feedforward regulation, soft-start, protection against feedback loop disconnection, inhibit for zero current consumption and thermal shutdown.
    The device is available in plastic dual in line, DIP8 for standard assembly, and SO16W for SMD assembly.

    Key Features

    • PROTECTION AGAINST FEEDBACK DISCONNECTION
    • INHIBIT FOR ZERO CURRENT CONSUMPTION
    • SOFT START FUNCTION
    • THERMAL SHUTDOWN
    • ZERO LOAD CURRENT OPERATION
    • VOLTAGE FEEDFORWARD
    • UP TO 1.5A STEP DOWN CONVERTER
    • PRECISE 3.3V (±1%) INTERNAL REFERENCE VOLTAGE
    • OPERATING INPUT VOLTAGE FROM 8V TO 55V
    • SWITCHING FREQUENCY ADJUSTABLE UP TO 300KHz
    • INTERNAL CURRENT LIMITING (PULSE-BY PULSE AND HICCUP MODE)
    • OUTPUT VOLTAGE ADJUSTABLE FROM 3.3V TO 50V

Recommended for you

Evaluation Tools

    • Part Number

      1.5 A step down switching regulator (VIN = 8 to 55 V) based on L4971

00 Files selected for download

Technical Documentation

    • Description Version Size Action
      DS1272
      1.5A step down switching regulator
      11.2
      568.86 KB
      PDF
      DS1272

      1.5A step down switching regulator

    • Description Version Size Action
      AN4070
      250 W grid connected microinverter
      1.0
      4.74 MB
      PDF
      AN937
      Designing with L4971, 1.5 A high efficiency DC-DC converter
      15.2
      1,008.47 KB
      PDF
      AN1941
      Low Voltage LED Driver Using L6920D, L4971 and L6902D
      1.5
      499.38 KB
      PDF
      AN4070

      250 W grid connected microinverter

      AN937

      Designing with L4971, 1.5 A high efficiency DC-DC converter

      AN1941

      Low Voltage LED Driver Using L6920D, L4971 and L6902D

    • Description Version Size Action
      TN1224
      Mounting instructions for SMD (surface mounting device) packages
      2.2
      1.06 MB
      PDF
      TN1224

      Mounting instructions for SMD (surface mounting device) packages

    • Description Version Size Action
      DN0010
      Adapting ST power line modem evaluation boards to communicate over a DC bus
      1.2
      404.54 KB
      PDF
      DN0011
      ST1S03 alternative topology: Using a buck in a negative buck-boost configuration
      1.2
      361.3 KB
      PDF
      DN0010

      Adapting ST power line modem evaluation boards to communicate over a DC bus

      DN0011

      ST1S03 alternative topology: Using a buck in a negative buck-boost configuration

Publications and Collaterals

    • Description Version Size Action
      Electric vehicle (EV) ecosystem 1.1
      1.28 MB
      PDF

      Electric vehicle (EV) ecosystem

Quality and Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
L4971
Active
DIP-8 Industrial Ecopack2
L4971D
Active
SO-16W Industrial Ecopack1
L4971D013TR
Active
SO-16W Industrial Ecopack1

L4971

Package:

DIP-8

Material Declaration**:

PDF XML

Marketing Status

Active

Package

DIP-8

Grade

Industrial

RoHS Compliance Grade

Ecopack2

L4971D

Package:

SO-16W

Material Declaration**:

PDF XML

Marketing Status

Active

Package

SO-16W

Grade

Industrial

RoHS Compliance Grade

Ecopack1

L4971D013TR

Package:

SO-16W

Material Declaration**:

PDF XML

Marketing Status

Active

Package

SO-16W

Grade

Industrial

RoHS Compliance Grade

Ecopack1

(**) The Material Declaration forms available on st.com may be generic documents based on the most commonly used package within a package family. For this reason, they may not be 100% accurate for a specific device. Please contact our sales support for information on specific devices.

eDesignSuite

Converter

Input

V This option is required. And must be less than or equal to Volt. Max [V]
V This option is required. And must be greater than or equal to Volt. Min [V]

Output Power

V This option is required and must be a number.
A This option is required and must be a number.

Sample & Buy

Part Number
Order from Distributors
Order from ST
Package
Packing Type
Marketing Status
ECCN (US)
Country of Origin
Budgetary Price (US$)*/Qty
L4971 Available at 7 distributors

Distributor availability ofL4971

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 1922 1 Order Now
COMPEL EUROPE 312 1 Order Now
RS COMPONENTS EUROPE 2386 1 Order Now
AVNET AMERICA 2508 0 Order Now
ARROW EUROPE 19450 0 Order Now
MOUSER WORLDWIDE 3618 1 Order Now
ANGLIA Live EUROPE 35200 50 Order Now

Distributor reported inventory date: 2020-06-29

Distributor Name

DIGIKEY

Stock

1922

Min.Order

1

Region

WORLDWIDE Order Now

COMPEL

Stock

312

Min.Order

1

Region

EUROPE Order Now

RS COMPONENTS

Stock

2386

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

2508

Min.Order

0

Region

AMERICA Order Now

ARROW

Stock

19450

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

3618

Min.Order

1

Region

WORLDWIDE Order Now

ANGLIA Live

Stock

35200

Min.Order

50

Region

EUROPE Order Now

Distributor reported inventory date: 2020-06-29

Get sample DIP-8 Tube
Active
EAR99 CHINA 1.185 / 1k
L4971D Available at 7 distributors

Distributor availability ofL4971D

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 62 1 Order Now
COMPEL EUROPE 31 1 Order Now
RS COMPONENTS EUROPE 215 1 Order Now
FUTURE WORLDWIDE 2152 1 Order Now
ARROW EUROPE 998 0 Order Now
MOUSER WORLDWIDE 1099 1 Order Now
Farnell Element14 EUROPE 1080 1 Order Now

Distributor reported inventory date: 2020-06-29

Distributor Name

DIGIKEY

Stock

62

Min.Order

1

Region

WORLDWIDE Order Now

COMPEL

Stock

31

Min.Order

1

Region

EUROPE Order Now

RS COMPONENTS

Stock

215

Min.Order

1

Region

EUROPE Order Now

FUTURE

Stock

2152

Min.Order

1

Region

WORLDWIDE Order Now

ARROW

Stock

998

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

1099

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

1080

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2020-06-29

Buy now SO-16W Tube
Active
EAR99 MALAYSIA 1.354 / 1k
L4971D013TR Available at 5 distributors

Distributor availability ofL4971D013TR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 989 1 Order Now
COMPEL EUROPE 2797 1 Order Now
AVNET AMERICA 30000 0 Order Now
ARROW AMERICA 5000 1000 Order Now
Farnell Element14 EUROPE 656 1 Order Now

Distributor reported inventory date: 2020-06-29

Distributor Name

DIGIKEY

Stock

989

Min.Order

1

Region

WORLDWIDE Order Now

COMPEL

Stock

2797

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

30000

Min.Order

0

Region

AMERICA Order Now

ARROW

Stock

5000

Min.Order

1000

Region

AMERICA Order Now

Farnell Element14

Stock

656

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2020-06-29

Get sample SO-16W Tape And Reel
Active
EAR99 MALAYSIA 1.354 / 1k

L4971

Package

DIP-8

Packing Type

Tube

Budgetary Price (US$)*/Qty

1.185 / 1k

Distributor availability ofL4971

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 1922 1 Order Now
COMPEL EUROPE 312 1 Order Now
RS COMPONENTS EUROPE 2386 1 Order Now
AVNET AMERICA 2508 0 Order Now
ARROW EUROPE 19450 0 Order Now
MOUSER WORLDWIDE 3618 1 Order Now
ANGLIA Live EUROPE 35200 50 Order Now

Distributor reported inventory date: 2020-06-29

Distributor Name

DIGIKEY

Stock

1922

Min.Order

1

Region

WORLDWIDE Order Now

COMPEL

Stock

312

Min.Order

1

Region

EUROPE Order Now

RS COMPONENTS

Stock

2386

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

2508

Min.Order

0

Region

AMERICA Order Now

ARROW

Stock

19450

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

3618

Min.Order

1

Region

WORLDWIDE Order Now

ANGLIA Live

Stock

35200

Min.Order

50

Region

EUROPE Order Now

Distributor reported inventory date: 2020-06-29

Marketing Status

Active

Budgetary Price (US$)* / Qty

1.185 / 1k

ECCN (US)

EAR99

Country of Origin

CHINA

L4971D

Package

SO-16W

Packing Type

Tube

Budgetary Price (US$)*/Qty

1.354 / 1k

Distributor availability ofL4971D

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 62 1 Order Now
COMPEL EUROPE 31 1 Order Now
RS COMPONENTS EUROPE 215 1 Order Now
FUTURE WORLDWIDE 2152 1 Order Now
ARROW EUROPE 998 0 Order Now
MOUSER WORLDWIDE 1099 1 Order Now
Farnell Element14 EUROPE 1080 1 Order Now

Distributor reported inventory date: 2020-06-29

Distributor Name

DIGIKEY

Stock

62

Min.Order

1

Region

WORLDWIDE Order Now

COMPEL

Stock

31

Min.Order

1

Region

EUROPE Order Now

RS COMPONENTS

Stock

215

Min.Order

1

Region

EUROPE Order Now

FUTURE

Stock

2152

Min.Order

1

Region

WORLDWIDE Order Now

ARROW

Stock

998

Min.Order

0

Region

EUROPE Order Now

MOUSER

Stock

1099

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

1080

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2020-06-29

Marketing Status

Active

Budgetary Price (US$)* / Qty

1.354 / 1k

ECCN (US)

EAR99

Country of Origin

MALAYSIA

L4971D013TR

Package

SO-16W

Packing Type

Tape And Reel

Budgetary Price (US$)*/Qty

1.354 / 1k

Distributor availability ofL4971D013TR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 989 1 Order Now
COMPEL EUROPE 2797 1 Order Now
AVNET AMERICA 30000 0 Order Now
ARROW AMERICA 5000 1000 Order Now
Farnell Element14 EUROPE 656 1 Order Now

Distributor reported inventory date: 2020-06-29

Distributor Name

DIGIKEY

Stock

989

Min.Order

1

Region

WORLDWIDE Order Now

COMPEL

Stock

2797

Min.Order

1

Region

EUROPE Order Now

AVNET

Stock

30000

Min.Order

0

Region

AMERICA Order Now

ARROW

Stock

5000

Min.Order

1000

Region

AMERICA Order Now

Farnell Element14

Stock

656

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2020-06-29

Marketing Status

Active

Budgetary Price (US$)* / Qty

1.354 / 1k

ECCN (US)

EAR99

Country of Origin

MALAYSIA

(*) Suggested Resale Price per unit (USD) for BUDGETARY USE ONLY. For quotes, prices in local currency, please contact your local ST Sales Office  or our Distributors