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3 A step-down monolithic switching regulator
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The PM8903 is a high efficiency monolithic step-down switching regulator designed to deliver up to 3 A continuous current. The IC operates from 2.8 V to 6 V input voltage (VIN).

The PM8903 features low-resistance integrated nMOS and proprietary pulse-skipping mode for optimum efficiency over all the loading range.

The voltage mode control loop allows the widest range of output filter. Current sense is internally thermally compensated for optimum precision.

The integrated 0.6 V reference allows the regulation of output voltages with ±1% accuracy over temperature variations. Switching frequency is typically set to 1.1 MHz and can be programmed to 0.8 MHz or 1.0 MHz. Out of phase synchronization allows the reduction of input RMS current.

The PM8903 provides precise dual-threshold overcurrent protection as well as over / undervoltage and overtemperature protection. PGOOD output easily provides real-time information on the output voltage.

The PM8903 is available in VFQFPN16 3 x 3 mm.

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Errata Sheet
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Key Features

  • Integrated 35 mΩ MOSFETs for high efficiency
  • 3 A continuous output current
  • 2.8 V to 6 V input voltage (VIN)
  • 2.9 V to 5.5 V supply voltage (VCC)
  • Adjustable output voltage down to 0.6 V
  • 1% output voltage accuracy
  • 1.1 MHz switching frequency operation
  • PSKIP mode to optimize light load efficiency
  • Embedded bootstrap diode
  • Thermally compensated loss-less current sense across HS and LS MOSFETs
  • OV/UV/OC and overtemperature protection
  • Internal soft-start and soft-stop
  • Interleaving synchronization (Up to 2 ICs)
  • Power Good output
  • Shutdown function (<15 μA quiescent current)
  • VFQFPN16 3 x 3 mm compact package

Design Resources


Technical Documentation

Product Specifications

Description Version Size
DS8864: 3 A step-down monolithic switching regulator
1.0 2,127 KB

Application Notes

Description Version Size
AN4086: Buck voltage regulator using the PM8903
1.0 1,424 KB

Sample & Buy

Part Number Marketing StatusPackagePacking TypeAutomotive GradeOrder From STUnit Price (US$)*
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Material Declaration**
PM8903TRActiveVFQFPN 16 3x3x1.0Tape And Reel_-No availability reported, please contact our Sales officeEcopack2PDF

(*) 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
(**) The Material Declaration forms available on 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.