5 V-2 A, 115 kHz flyback with temporary extra-power management based on the VIPER28HN

The STEVAL-ISA126V1 is a 5 V-2 A application with 3.3 A peak current capability for 1.9 sec, using VIPer28H, a new off-line high voltage converter from STMicroelectronics.

In some applications an SMPS, normally supposed to deliver a certain amount of power, from time to time undergoes load peaks that can be even two or more times as much, but only for a time interval which is short if compared to the thermal time constants of the power components. Typical examples of such loads are printers and audio systems.

In these cases, it is more cost-effective to thermally design the system for the maximum continuous power and not for the peak power demand, which will be sustained only for a limited time window.

Such a design is possible thanks to the EPT function of VIPER28H, which allows the designer to fix the maximum time window during which the converter is able to manage the peak power still maintaining output voltage regulation. If the overload lasts more than this time window, the converter is automatically shut down in auto-restart mode, in order to avoid the damaging of the power components.

Key Features

  • Input voltage range: 90 VRMS to 265 VRMS
  • Output voltage: 5 V
  • Max output current: IOUTmax 2 A
  • Peak output current: IOUTpk 3 A
  • Precision of output regulation: ΔVOUT_LF ±5%
  • High frequency output voltage ripple: ΔVOUT_HF 50 mV
  • Max ambient operating temperature: TA 60 ºC
  • 800 V avalanche rugged power section
  • PWM operation , at 115 kHz with frequency jittering for lower EMI
  • Limiting current with adjustable set point
  • On-board soft-start
  • Safe auto-restart after a fault condition, low standby power (< 50 mW at 265 Vac)
  • Adjustable and accurate over voltage protection, thermal shutdown with hysteresis, delayed overload protection
  • RoHS compliant





Description バージョン サイズ
DB2091 DB2091: 5 V-2 A, 115 kHz flyback with temporary extra-power management based on the VIPER28HN 1.0 154 KB


Board Manufacturing Specifications
Description バージョン サイズ
STEVAL-ISA126V1 gerber files 1.0 485 KB
Bill of Materials
Description バージョン サイズ
STEVAL-ISA126V1 BOM 1.0 118 KB
Schematic Packs
Description バージョン サイズ
STEVAL-ISA126V1 schematics 1.0 86 KB


Description バージョン サイズ
Evaluation products license agreement 1.0 125 KB
サポート & コミュニティ

サンプル & 購入

製品型番 Core Product Marketing Status Unit Price (US$) * 数量 ECCN (EU) ECCN (US) Country of Origin More info Order from ST Order from Distributors

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品質 & 信頼性

製品型番 Marketing Status パッケージ Grade RoHS Compliance Grade Material Declaration**
STEVAL-ISA126V1 アクティブCARDIndustrialEcopack2

(**) 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.