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In its various implementations including primary side and secondary side regulation, fixed switching frequency or quasi resonant operation, an isolated or non-isolated flyback topology is most often found in off-line converters for an output power ranging from a few watts up to 100 W.

The circuit operation is based on a single switch topology and the energy taken from the input is stored in the transformer’s primary inductance while the power switch is switched on, and transferred to the secondary output when the power switch is switched off.

Efficiency, power density and low stand-by power together are key requirements for flyback topologies together with reliability.

In addition to a range of controllers, power MOSFETs and integrated high-voltage converters as well as diodes and protection devices, ST offers a full set of hardware and software development and evaluation tools to help design high-efficiency, flyback AC-DC converters.

Flyback Converter block diagrams

00 Files selected for download

Technical Documentation

    • Description Version Size Action
      AN4685
      12 V, 10 W isolated flyback converter based on VIPer25HD
      1.0
      1.73 MB
      PDF
      AN4479
      12 V, 15 W peak 20 W isolated flyback converter based on VIPer38LE
      1.0
      1.08 MB
      PDF
      AN4260
      12 V, 150 mA non-isolated buck converter using the VIPER06XS, from the VIPer™ plus family
      4.2
      3.5 MB
      PDF
      AN4940
      12 V, 7.2 W VIPer0P IR remote controlled flyback topology for air conditioning applications using VIPer0P
      1.0
      9.29 MB
      PDF
      AN4924
      12 V, 8.4 W peak power 30 W isolated flyback converter using VIPer38HD
      1.0
      2.94 MB
      PDF
      AN4812
      15 W, 12 V output, isolated flyback converter using Viper35HD device from the VIPer™ Plus family of high voltage converters
      2.0
      2.43 MB
      PDF
      AN4830
      15 W, 5 V - 12 V double output, isolated flyback converter based on Viper37LE/D
      1.0
      3.13 MB
      PDF
      AN4896
      15 W, 5 V output USB adapter using STCH02
      1.0
      2.18 MB
      PDF
      AN5030
      16 W, triple output, quasi-resonant flyback converter for air conditioning applications using VIPerPlus – VIPER35LD
      1.0
      2.06 MB
      PDF
      AN4410
      3 W, 5 V isolated flyback converter using the VIPer06HN, from the VIPer™ plus family
      2.0
      1.41 MB
      PDF
      AN4418
      3 W, 5 V isolated flyback converter using the VIPer06HS, from the VIPer™ plus family
      2.0
      1.38 MB
      PDF
      AN2811
      3.5 W non-isolated offline constant-current LED driver based on VIPER17
      1.2
      1.13 MB
      PDF
      AN1439
      30 W AC-DC adapter with the L6565 quasi-resonant PWM controller
      7.0
      301.08 KB
      PDF
      AN5316
      35 W wide input range flyback converter using HVLED001B quasi-resonant flyback controller and STF10LN80K5
      2.0
      3.96 MB
      PDF
      AN5335
      35W transition-mode flyback converter with ultra-low THD based on HVLED007
      1.2
      3.36 MB
      PDF
      AN4404
      4 W, 12 V isolated flyback converter using the VIPer06HS, from the VIPer™ plus family
      2.0
      1.37 MB
      PDF
      AN5442
      45W USB Type-C™ PD adapter board with controllers STCH03 QR flyback,SRK1001 adaptive synchronous rectifier and STUSB4761 USB Type-C™ PD
      1.1
      14.03 MB
      PDF
      AN2753
      6 W single-output VIPer17 demonstration board
      2.1
      1.39 MB
      PDF
      AN4941
      7 W dual output (-5 V/+7 V) non-isolated flyback converter with capacitive touch sensing using VIPer0P and STM32L052
      1.0
      3.43 MB
      PDF
      AN1768
      ADMISSIBLE AVALANCHE POWER OF SCHOTTKY DIODES
      1.1
      46.82 KB
      PDF
      AN4407
      Advantage of the use of an added driver source lead in discrete Power MOSFETs
      2.0
      5.42 MB
      PDF
      AN2025
      CONVERTER IMPROVEMENT USING SCHOTTKY RECTIFIER AVALANCHE SPECIFICATION
      1.1
      147.59 KB
      PDF
      AN604
      Calculation of conduction losses in a power rectifier
      3.2
      137.74 KB
      PDF
      AN4021
      Calculation of reverse losses in a power diode
      1.0
      120.47 KB
      PDF
      AN4381
      Current sharing in parallel diodes
      1.0
      449.12 KB
      PDF
      AN3028
      EVLVIP16L-4WFN: 16 V / 4.5 W, 60 kHz non-isolated flyback demonstration board using the VIPer16LN
      1.0
      1.13 MB
      PDF
      AN2840
      EVLVIP17-5WCHG: 5 W low standby consumption battery charger demonstration board based on the VIPER17HN
      1.1
      651.9 KB
      PDF
      AN4106
      EVLVIP26L-12WFN: 12 V/12 W, 60 kHz non-isolated flyback
      1.0
      3.4 MB
      PDF
      AN2950
      EVLVIPER28L-10W: 5 V/10 W, 60 kHz isolated flyback with extra power management
      1.0
      1.76 MB
      PDF
      AN4932
      HVLED001A - enhanced QR high power factor flyback controller for LED drivers
      2.0
      3.01 MB
      PDF
      AN1326
      L6565 quasi-resonant controller
      7.3
      543.01 KB
      PDF
      AN1453
      NEW FAMILY OF 150V POWER SCHOTTKY
      1.1
      131.48 KB
      PDF
      AN5046
      Printed circuit board assembly recommendations for STMicroelectronics PowerFLAT packages
      4.0
      4.82 MB
      PDF
      AN5088
      Rectifiers thermal management, handling and mounting recommendations
      2.0
      2.32 MB
      PDF
      AN533
      SCRs, TRIACs, and AC switches, thermal management precautions for handling and mounting
      3.6
      217.19 KB
      PDF
      AN443
      SERIES OPERATION ON FAST RECTIFIERS
      2.1
      202.48 KB
      PDF
      AN5333
      SRK1001 adaptive synchronous rectification controller for flyback converters evaluation board family
      1.0
      1.75 MB
      PDF
      AN2934
      STEVAL-ISA062V1: 6 W, wide-range dual and single output SMPS demonstration board based on the VIPer17
      1.0
      1.65 MB
      PDF
      AN4165
      STEVAL-ISA111V1: 12 V / 12 W, 115 kHz non-isolated flyback
      2.0
      2.47 MB
      PDF
      AN4116
      STEVAL-ISA112V1: 12 V/4 W, 115 kHz non-isolated flyback
      1.0
      3.69 MB
      PDF
      AN4164
      STEVAL-ISA113V1: 12 V/4 W, 115 kHz non-isolated flyback
      1.0
      5.23 MB
      PDF
      AN4273
      STEVAL-ISA114V1: 5 V / 0.8 W 30 kHz buck with the VIPer06XS
      3.0
      978.71 KB
      PDF
      AN4562
      STEVAL-ISA116V1: 5 W, 2 output wide range buck converter based on the VIPER26LD
      1.0
      896.83 KB
      PDF
      AN4259
      STEVAL-ISA117V1 12 V / 4.2 W, 60 kHz flyback isolated with VIPer16LN
      3.0
      1.71 MB
      PDF
      AN4345
      STEVAL-ISA119V1: 1.5 W double output buck product evaluation board based on the VIPER16LD
      1.0
      2.84 MB
      PDF
      AN4372
      STEVAL-ISA134V1: 12 V / 4 W, 115 kHz isolated flyback
      2.0
      1.33 MB
      PDF
      AN4836
      STEVAL-ISA174V1: VIPer0P 7 W double output non-isolated flyback
      2.0
      4.05 MB
      PDF
      AN4878
      STEVAL-ISA175V1 three-output isolated flyback converter for smart meter and power line communication systems based on VIPER26HD
      1.0
      2.15 MB
      PDF
      AN4855
      STEVAL-ISA177V1 5 V/4.25 W non-isolated flyback demo with VIPer01
      2.0
      8.82 MB
      PDF
      AN4858
      STEVAL-ISA178V1 5 V/1 W 30 kHz buck demo with VIPer01
      1.0
      1.84 MB
      PDF
      AN4857
      STEVAL-ISA179V1 15 V/2.25 W 60 kHz buck demo with VIPer0P
      1.0
      1.61 MB
      PDF
      AN4905
      STEVAL-ISA180V1 12 V/0.6 A isolated flyback demo with VIPer0P
      1.0
      2.55 MB
      PDF
      AN2945
      STM8S and STM32™ MCUs: a consistent 8/32-bit product line for painless migration
      1.4
      209.97 KB
      PDF
      AN2872
      Super wide-range buck converter based on the VIPer16
      1.2
      581.24 KB
      PDF
      AN1542
      THE THERMAL RUNAWAY LAW IN SCHOTTKY USED IN OR-ING APPLICATION
      1.1
      57.47 KB
      PDF
      AN869
      Tj max limit of Schottky diodes
      2.2
      60.9 KB
      PDF
      AN4419
      VIPER37HE: 15 W wide range single output evaluation board
      1.0
      1.42 MB
      PDF
      AN2929
      Wide range [90 V - 265 V] input, 5 V - 12 W output VIPER27LN demonstration board with improved standby performance
      2.0
      1.44 MB
      PDF
      AN3011
      Wide range input (90 - 265), single output (5 V-11 W) EVLVIP27H-12SB, VIPer27 demonstration board
      1.1
      1.76 MB
      PDF
      AN4685

      12 V, 10 W isolated flyback converter based on VIPer25HD

      AN4479

      12 V, 15 W peak 20 W isolated flyback converter based on VIPer38LE

      AN4260

      12 V, 150 mA non-isolated buck converter using the VIPER06XS, from the VIPer™ plus family

      AN4940

      12 V, 7.2 W VIPer0P IR remote controlled flyback topology for air conditioning applications using VIPer0P

      AN4924

      12 V, 8.4 W peak power 30 W isolated flyback converter using VIPer38HD

      AN4812

      15 W, 12 V output, isolated flyback converter using Viper35HD device from the VIPer™ Plus family of high voltage converters

      AN4830

      15 W, 5 V - 12 V double output, isolated flyback converter based on Viper37LE/D

      AN4896

      15 W, 5 V output USB adapter using STCH02

      AN5030

      16 W, triple output, quasi-resonant flyback converter for air conditioning applications using VIPerPlus – VIPER35LD

      AN4410

      3 W, 5 V isolated flyback converter using the VIPer06HN, from the VIPer™ plus family

      AN4418

      3 W, 5 V isolated flyback converter using the VIPer06HS, from the VIPer™ plus family

      AN2811

      3.5 W non-isolated offline constant-current LED driver based on VIPER17

      AN1439

      30 W AC-DC adapter with the L6565 quasi-resonant PWM controller

      AN5316

      35 W wide input range flyback converter using HVLED001B quasi-resonant flyback controller and STF10LN80K5

      AN5335

      35W transition-mode flyback converter with ultra-low THD based on HVLED007

      AN4404

      4 W, 12 V isolated flyback converter using the VIPer06HS, from the VIPer™ plus family

      AN5442

      45W USB Type-C™ PD adapter board with controllers STCH03 QR flyback,SRK1001 adaptive synchronous rectifier and STUSB4761 USB Type-C™ PD

      AN2753

      6 W single-output VIPer17 demonstration board

      AN4941

      7 W dual output (-5 V/+7 V) non-isolated flyback converter with capacitive touch sensing using VIPer0P and STM32L052

      AN1768

      ADMISSIBLE AVALANCHE POWER OF SCHOTTKY DIODES

      AN4407

      Advantage of the use of an added driver source lead in discrete Power MOSFETs

      AN2025

      CONVERTER IMPROVEMENT USING SCHOTTKY RECTIFIER AVALANCHE SPECIFICATION

      AN604

      Calculation of conduction losses in a power rectifier

      AN4021

      Calculation of reverse losses in a power diode

      AN4381

      Current sharing in parallel diodes

      AN3028

      EVLVIP16L-4WFN: 16 V / 4.5 W, 60 kHz non-isolated flyback demonstration board using the VIPer16LN

      AN2840

      EVLVIP17-5WCHG: 5 W low standby consumption battery charger demonstration board based on the VIPER17HN

      AN4106

      EVLVIP26L-12WFN: 12 V/12 W, 60 kHz non-isolated flyback

      AN2950

      EVLVIPER28L-10W: 5 V/10 W, 60 kHz isolated flyback with extra power management

      AN4932

      HVLED001A - enhanced QR high power factor flyback controller for LED drivers

      AN1326

      L6565 quasi-resonant controller

      AN1453

      NEW FAMILY OF 150V POWER SCHOTTKY

      AN5046

      Printed circuit board assembly recommendations for STMicroelectronics PowerFLAT packages

      AN5088

      Rectifiers thermal management, handling and mounting recommendations

      AN533

      SCRs, TRIACs, and AC switches, thermal management precautions for handling and mounting

      AN443

      SERIES OPERATION ON FAST RECTIFIERS

      AN5333

      SRK1001 adaptive synchronous rectification controller for flyback converters evaluation board family

      AN2934

      STEVAL-ISA062V1: 6 W, wide-range dual and single output SMPS demonstration board based on the VIPer17

      AN4165

      STEVAL-ISA111V1: 12 V / 12 W, 115 kHz non-isolated flyback

      AN4116

      STEVAL-ISA112V1: 12 V/4 W, 115 kHz non-isolated flyback

      AN4164

      STEVAL-ISA113V1: 12 V/4 W, 115 kHz non-isolated flyback

      AN4273

      STEVAL-ISA114V1: 5 V / 0.8 W 30 kHz buck with the VIPer06XS

      AN4562

      STEVAL-ISA116V1: 5 W, 2 output wide range buck converter based on the VIPER26LD

      AN4259

      STEVAL-ISA117V1 12 V / 4.2 W, 60 kHz flyback isolated with VIPer16LN

      AN4345

      STEVAL-ISA119V1: 1.5 W double output buck product evaluation board based on the VIPER16LD

      AN4372

      STEVAL-ISA134V1: 12 V / 4 W, 115 kHz isolated flyback

      AN4836

      STEVAL-ISA174V1: VIPer0P 7 W double output non-isolated flyback

      AN4878

      STEVAL-ISA175V1 three-output isolated flyback converter for smart meter and power line communication systems based on VIPER26HD

      AN4855

      STEVAL-ISA177V1 5 V/4.25 W non-isolated flyback demo with VIPer01

      AN4858

      STEVAL-ISA178V1 5 V/1 W 30 kHz buck demo with VIPer01

      AN4857

      STEVAL-ISA179V1 15 V/2.25 W 60 kHz buck demo with VIPer0P

      AN4905

      STEVAL-ISA180V1 12 V/0.6 A isolated flyback demo with VIPer0P

      AN2945

      STM8S and STM32™ MCUs: a consistent 8/32-bit product line for painless migration

      AN2872

      Super wide-range buck converter based on the VIPer16

      AN1542

      THE THERMAL RUNAWAY LAW IN SCHOTTKY USED IN OR-ING APPLICATION

      AN869

      Tj max limit of Schottky diodes

      AN4419

      VIPER37HE: 15 W wide range single output evaluation board

      AN2929

      Wide range [90 V - 265 V] input, 5 V - 12 W output VIPER27LN demonstration board with improved standby performance

      AN3011

      Wide range input (90 - 265), single output (5 V-11 W) EVLVIP27H-12SB, VIPer27 demonstration board

    • Description Version Size Action
      DN0039
      35 W wide input range flyback converter using HVLED001A quasi resonant Flyback controller and STF10LN80K5
      1.1
      1 MB
      PDF
      DN0009
      VIPer06X buck regulator, 12V 140 mA
      1.2
      493.06 KB
      PDF
      DN0039

      35 W wide input range flyback converter using HVLED001A quasi resonant Flyback controller and STF10LN80K5

      DN0009

      VIPer06X buck regulator, 12V 140 mA

Presentations & Training Material

    • Description Version Size Action
      Primary side regulation controllers portfolio
      1.1 MB
      PDF

      Primary side regulation controllers portfolio

Publications and Collaterals

    • Description Version Size Action
      1200V SiC diodes, 2 to 40 A in surface-mount and through-hole packages 1.0
      748.77 KB
      PDF
      800-1050V MDmesh™ K5 ST’s first super-junction VHV MOSFET Series 1.0
      516.44 KB
      PDF
      800-1700 V MDmesh K5: Very high voltage super-junction Power MOSFET series 1.0
      477.67 KB
      PDF
      SOD128Flat power Schottky diodes for improved cost and space-savings 1.0
      2.18 MB
      PDF
      ST Diodes Finder : the new app for Android and iOS 2.0
      1.46 MB
      PDF

      1200V SiC diodes, 2 to 40 A in surface-mount and through-hole packages

      800-1050V MDmesh™ K5 ST’s first super-junction VHV MOSFET Series

      800-1700 V MDmesh K5: Very high voltage super-junction Power MOSFET series

      SOD128Flat power Schottky diodes for improved cost and space-savings

      ST Diodes Finder : the new app for Android and iOS

    • Description Version Size Action
      Diodes and rectifiers selection guide 2.0
      815.09 KB
      PDF

      Diodes and rectifiers selection guide

    • Description Version Size Action
      VIPerPlus - Bring a Plus to your SMPS design 05.2020
      481.54 KB
      PDF
      VIPerPlus evaluation boards 05.2018
      1,002.52 KB
      PDF

      VIPerPlus - Bring a Plus to your SMPS design

      VIPerPlus evaluation boards

eDesignSuite

Converter

Input

V This option is required. And must be less than or equal to Volt. Max [V]
V This option is required. And must be greater than or equal to Volt. Min [V]

Output Power

V This option is required and must be a number.
A This option is required and must be a number.