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

The STEVAL-ISA084V1, based on the ST1S40, is an internally compensated 800 kHz fixed-frequency PWM synchronous step-down converter demonstration board.

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 (100% duty-cycle).

The ST1S40 integrates 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 device is protected through cycle-by-cycle current limiting in case of overload and is also protected by current foldback function with frequency reduction in case of short-circuit

The device is available with an enable on/off function.

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Data Brief

Key Features

  • Vin: 4 V to 18 V
  • Vout: 3.3 V
  • Maximum output current: 4 A
  • Switching frequency: 800 kHz
  • Short-circuit: protected
  • RoHS compliant


Design Resources


Technical Documentation

Product Specifications

Description Version Size
DB1494: 4 A peak, 800 kHz fixed-frequency PWM synchronous step-down demonstration board with enable on/off based on the ST1S40
1.0 103 KB

Hardware Resources

Board Manufacturing Specification

Description Version Size
STEVAL-ISA084V1 gerber files
4.1 143 KB

Bill of Materials

Description Version Size
1.0 37 KB

Schematic Pack

Description Version Size
STEVAL-ISA084V1 schematics
1.0 50 KB

Sample & Buy

Part Number Marketing StatusCore ProductOrder From STUnit Price (US$)*
@ 1
Distributor AvailabilityRoHS Compliance GradeDownload
Material Declaration**
STEVAL-ISA084V1ActiveST1S40IDRBuy Direct46.55Distributor reported inventory date: 2015-10-02
Distributor NameRegionStockMin. order
Newark Element14Order NowAMERICA20
Farnell Element14Order NowEUROPE51

(*) 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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