ST1S31:3 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
Product Specifications
DescriptionVersionSize
DS8977: 3 A DC step-down switching regulator4.01 MB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Solution Evaluation Tools
Part NumberManufacturerDescription
STEVAL-ISA069V13 A / 1.5 MHz step-down synchronous switching regulator based on the ST1S31 in DFN 3x3 package
STEVAL-ISA070V13 A / 1.5 MHz step-down synchronous switching regulator based on the ST1S31 in SO-8 package
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
ST1S31D-RSO-8Tape And Reel0.4711000NECEAR99CHINA
ST1S31PURVFDFPN 8 3x3x1.0Tape And Reel0.5351000NECEAR99MALAYSIA
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
ST1S31D-RSO-8IndustrialEcopack2
ST1S31PURVFDFPN 8 3x3x1.0IndustrialEcopack2md__59_vfdfpn-wspc-8-wspc-3x3_my59ua17aa5.pdf
md__59_vfdfpn-wspc-8-wspc-3x3_my59ua17aa5.xml
3 A DC step-down switching regulator ST1S31
Very low drop voltage regulators with inhibit KFXX
md__59_vfdfpn-wspc-8-wspc-3x3_my59ua17aa5.pdf ST1S31
md__59_vfdfpn-wspc-8-wspc-3x3_my59ua17aa5.xml ST1S31