3A DC step-down switching regulator

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  • The ST1S40 device is an internally compensated 850 kHz fixed-frequency PWM synchronous step-down regulator. The ST1S40 operates from 4.0 V to 18 V input, while it regulates an output voltage as low as 0.8 V and up to VIN.

    The ST1S40 integrates a 95 mΩ high side switch and 69 mΩ synchronous rectifier allowing very high efficiency with very low output voltages.
    The peak current mode control with internal compensation delivers a very compact solution with a minimum component count.
    The ST1S40 is available in HSOP-8, VFQFPN 4 mm x 4 mm - 8 lead, and standard SO8 package.

    Key Features

    • 3 A DC output current
    • 4.0 V to 18 V input voltage
    • Output voltage adjustable from 0.8 V
    • 850 kHz switching frequency
    • Internal soft-start
    • Integrated 95 mΩ and 69 mΩ Power MOSFETs
    • All ceramic capacitor
    • Enable
    • Cycle-by-cycle current limiting
    • Current fold back short-circuit protection
    • Available in HSOP-8, VFQFPN4x4-8L, and SO8 packages

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Part Number
Package
Packing Type
Marketing Status
Budgetary Price (US$)*
Quantity
ECCN (US)
Country of Origin
Order from Distributors
Order from ST
ST1S40IPHR PowerSO-8 Tape And Reel
Active
0.76 10000 EAR99 PHILIPPINES Check Availability

Distributor availability ofST1S40IPHR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 7680 1 Order Now
MOUSER WORLDWIDE 1827 1 Order Now
Farnell Element14 EUROPE 15 1 Order Now

Distributor reported inventory date: 2019-07-22

Distributor Name

DIGIKEY

Stock

7680

Min.Order

1

Region

WORLDWIDE Order Now

MOUSER

Stock

1827

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

15

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-07-22

Get sample
ST1S40IDR SO-8 Tape And Reel
Active
0.68 10000 EAR99 CHINA Check Availability

Distributor availability ofST1S40IDR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 21053 1 Order Now
ARROW EUROPE 10000 0 Order Now
Newark Element14 AMERICA 322 0 Order Now
MOUSER WORLDWIDE 3949 1 Order Now
Farnell Element14 EUROPE 200 1 Order Now

Distributor reported inventory date: 2019-07-22

Distributor Name

DIGIKEY

Stock

21053

Min.Order

1

Region

WORLDWIDE Order Now

ARROW

Stock

10000

Min.Order

0

Region

EUROPE Order Now

Newark Element14

Stock

322

Min.Order

0

Region

AMERICA Order Now

MOUSER

Stock

3949

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

200

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-07-22

Get sample
ST1S40IPUR DFN8 4x4 Tape And Reel
Active
0.798 10000 EAR99 MALAYSIA Check Availability

Distributor availability ofST1S40IPUR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 9225 1 Order Now
MOUSER WORLDWIDE 3894 1 Order Now

Distributor reported inventory date: 2019-07-22

Distributor Name

DIGIKEY

Stock

9225

Min.Order

1

Region

WORLDWIDE Order Now

MOUSER

Stock

3894

Min.Order

1

Region

WORLDWIDE Order Now

Distributor reported inventory date: 2019-07-22

Get sample

ST1S40IPHR

Package

PowerSO-8

Packing Type

Tape And Reel

Unit Price (US$)

0.76*

Distributor availability ofST1S40IPHR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 7680 1 Order Now
MOUSER WORLDWIDE 1827 1 Order Now
Farnell Element14 EUROPE 15 1 Order Now

Distributor reported inventory date: 2019-07-22

Distributor Name

DIGIKEY

Stock

7680

Min.Order

1

Region

WORLDWIDE Order Now

MOUSER

Stock

1827

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

15

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-07-22

Marketing Status

Active

Unit Price (US$)

0.76

Quantity

10000

ECCN (US)

EAR99

Country of Origin

PHILIPPINES

ST1S40IDR

Package

SO-8

Packing Type

Tape And Reel

Unit Price (US$)

0.68*

Distributor availability ofST1S40IDR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 21053 1 Order Now
ARROW EUROPE 10000 0 Order Now
Newark Element14 AMERICA 322 0 Order Now
MOUSER WORLDWIDE 3949 1 Order Now
Farnell Element14 EUROPE 200 1 Order Now

Distributor reported inventory date: 2019-07-22

Distributor Name

DIGIKEY

Stock

21053

Min.Order

1

Region

WORLDWIDE Order Now

ARROW

Stock

10000

Min.Order

0

Region

EUROPE Order Now

Newark Element14

Stock

322

Min.Order

0

Region

AMERICA Order Now

MOUSER

Stock

3949

Min.Order

1

Region

WORLDWIDE Order Now

Farnell Element14

Stock

200

Min.Order

1

Region

EUROPE Order Now

Distributor reported inventory date: 2019-07-22

Marketing Status

Active

Unit Price (US$)

0.68

Quantity

10000

ECCN (US)

EAR99

Country of Origin

CHINA

ST1S40IPUR

Package

DFN8 4x4

Packing Type

Tape And Reel

Unit Price (US$)

0.798*

Distributor availability ofST1S40IPUR

Distributor Name
Region Stock Min. Order Third party link
DIGIKEY WORLDWIDE 9225 1 Order Now
MOUSER WORLDWIDE 3894 1 Order Now

Distributor reported inventory date: 2019-07-22

Distributor Name

DIGIKEY

Stock

9225

Min.Order

1

Region

WORLDWIDE Order Now

MOUSER

Stock

3894

Min.Order

1

Region

WORLDWIDE Order Now

Distributor reported inventory date: 2019-07-22

Marketing Status

Active

Unit Price (US$)

0.798

Quantity

10000

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

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Evaluation Tools

    • Part Number

      4 A peak, 800 kHz fixed-frequency PWM synchronous step-down demonstration board with enable on/off based on the ST1S40

00 Files selected for download

Technical Documentation

    • Description Version Size Action
      DS6942
      3 A DC step-down switching regulator
      5.0
      1.02 MB
      PDF
      DS6942

      3 A DC step-down switching regulator

Publications and Collaterals

    • Description Version Size Action
      Electric vehicle (EV) ecosystem 1.1
      1.28 MB
      PDF
      Peripheral semiconductors for set-top box applications 4.3
      633.85 KB
      PDF
      Switching Converters (DC-DC) – Quick Reference Guide 1.0
      481.92 KB
      PDF

      Electric vehicle (EV) ecosystem

      Peripheral semiconductors for set-top box applications

      Switching Converters (DC-DC) – Quick Reference Guide

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
ST1S40IDR
Active
SO-8 Industrial Ecopack2
ST1S40IPHR
Active
PowerSO-8 Industrial Ecopack2
ST1S40IPUR
Active
DFN8 4x4 Industrial Ecopack2

ST1S40IDR

Package:

SO-8

Material Declaration**:

PDF XML

Marketing Status

Active

Package

SO-8

Grade

Industrial

RoHS Compliance Grade

Ecopack2

ST1S40IPHR

Package:

PowerSO-8

Material Declaration**:

Marketing Status

Active

Package

PowerSO-8

Grade

Industrial

RoHS Compliance Grade

Ecopack2

ST1S40IPUR

Package:

DFN8 4x4

Material Declaration**:

Marketing Status

Active

Package

DFN8 4x4

Grade

Industrial

RoHS Compliance Grade

Ecopack2

(**) 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.