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1 A step down switching regulator
  • active Active

The L4976 is a step down monolithic power switching regulator delivering 1A 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 Rds(ON) of 0.25W) 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 40V 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, protection against feedback loop disconnection and thermal shutdown. The device is available in plastic dual in line, DIP8 for standard assembly, and SO16W for SMD assembly.

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Errata Sheet
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Key Features

  • Up to 1A step down converter
  • Operating input voltage from 8v to 55v
  • Precise 5.1V reference voltage
  • Output voltage adjustable from 0.5V to 50V
  • Switching frequency adjustable up to 300kHz
  • Voltage feedforward
  • Zero load current operation
  • Internal current limiting (pulse-bypulse
  • and hiccup mode)
  • Protection against feedback disconnection
  • Thermal shutdown

Circuit Diagram

Design Resources


Technical Documentation

Product Specifications

Description Version Size
DS1411: 1A step down switching regulator
7.2 254 KB

User Manual

Description Version Size
UM0971: STEVAL-IHM031V1 low voltage three-phase inverter demonstration board
1.1 1,139 KB

Design Notes & Tips

Description Version Size
DN0011: ST1S03 alternative topology: Using a buck in a negative buck-boost configuration
1.0 359 KB

Sample & Buy

Part Number Marketing StatusPackagePacking TypeAutomotive GradeOrder From STUnit Price (US$)*
@ 1000
Distributor AvailabilityRoHS Compliance GradeDownload
Material Declaration**
L4976ActiveDIP-8Tube_-1.523Distributor reported inventory date: 2015-11-25
Distributor NameRegionStockMin. order
ARROWOrder NowAMERICA2372000
Ecopack2 (**)-
L4976DActiveSO-16WTube_-1.607Distributor reported inventory date: 2015-11-28
Distributor NameRegionStockMin. order
L4976D013TRActiveSO-16WTape And Reel_Free Samples1.607Distributor reported inventory date: 2015-11-28
Distributor NameRegionStockMin. order

(*) 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.
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