3 A DC step-down switching regulator

The ST1S31 device is an internally compensated 1.5 MHz fixed-frequency PWM synchronous step-down regulator. The ST1S31 operates from 2.8 V to 5.5 V input, while it regulates an output voltage as low as 0.8 V and up to VIN.

The ST1S31 integrates a 60 mΩ high-side switch and a 45 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 ST1S31 device is available in 3 mm x 3 mm, 8 lead VFDFPN and SO8 packages.

Key Features

  • 3 A DC output current
  • 2.8 V to 5.5 V input voltage
  • Output voltage adjustable from 0.8 V
  • 1.5 MHz switching frequency
  • Internal soft-start and enable
  • Integrated 60 mΩ and 45 mΩ power MOSFETs
  • All ceramic capacitor
  • Power Good (POR)
  • Cycle-by-cycle current limiting
  • Current foldback short-circuit protection
  • VFDFPN 3 x 3 - 8L, SO8 packages

Resources

Technical Documentation

Product Specifications
Description Version Size
DS8977 DS8977: 3 A DC step-down switching regulator 4.0 1 MB

Publications and Collaterals

Brochures
Description Version Size
Brochure Power management guide 09.2017 3 MB

Tools and Software

Evaluation Tools
Solution Evaluation Tools
eDesignSuite Support & Community


Sample & Buy

Part Number Package Packing Type Marketing Status Unit Price (US$) * Quantity ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors
ST1S31D-R SO-8 Tape And Reel Active 0.471 1000 NEC EAR99 CHINA MORE INFO DISTRIBUTOR AVAILABILITY
ST1S31PUR VFDFPN 8 3x3x1.0 Tape And Reel Active 0.535 1000 NEC EAR99 MALAYSIA MORE INFO DISTRIBUTOR AVAILABILITY
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(*) 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

Quality & Reliability

Part Number Marketing Status Package Grade RoHS Compliance Grade Material Declaration**
ST1S31D-R ActiveSO-8IndustrialEcopack2
ST1S31PUR ActiveVFDFPN 8 3x3x1.0IndustrialEcopack2 0 0
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(**) 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.

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