Flyback SMPS Calculator

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One kind of switched-mode power supply is the Flyback SMPS, which functions by storing energy in a transformer during one portion of the switching cycle and transferring it to the output during another.
It usually consists of a transformer, capacitor, diode, and switching transistor placed in a certain order to effectively convert input voltage to the intended output voltage.

The main function of the Flyback SMPS is to convert an unregulated or fluctuating input voltage source into a regulated output voltage.
In order to provide a steady and controlled output voltage, it quickly cycles the input voltage on and off, stores energy during the off cycle, and transfers it to the output during the on cycle.

Understanding Flyback SMPS:

Design and Operation:

The flyback SMPS design encompasses two distinct operational phases: the primary side and the secondary side. The primary side interfaces with the input power source, while the secondary side connects to the output load. Central to the flyback design is the transformer, which facilitates power transfer from the primary to the secondary side.

A primary side switch, often a MOSFET or IGBT, is cycled on and off at a high frequency, typically ranging from 50 kHz to 200 kHz. This action generates a high-frequency AC voltage on the primary side, subsequently transformed into a high-voltage DC voltage on the secondary side by the transformer.


High efficiency:Flyback SMPS can attain remarkable efficiency levels, often exceeding 90%, primarily attributed to the transformer’s role in voltage upconversion and current reduction.

Small size: The integration of a transformer in flyback SMPS designs enables the creation of remarkably compact configurations, contributing to reduced overall size.

Low cost: Employing a transformer in flyback SMPS designs renders them cost-effective solutions, as transformers are comparatively economical components.

Isolation: Flyback SMPS offers galvanic isolation between the input and output, a critical feature for enhancing safety and minimizing noise interference.


Complexity:Designing a Flyback SMPS entails implementing a sophisticated control circuit to manage switching frequency and voltage regulation, potentially adding complexity to the design and debugging processes.

Noise: In certain applications, the high-frequency switching of the primary side switch in Flyback SMPS can lead to noise generation, posing a potential issue.

EMI: Flyback SMPS may produce electromagnetic interference (EMI), presenting challenges in certain applications where EMI is a concern.


  • Consumer Electronics
  • LED Lighting
  • Telecommunications
  • Industrial Automation
  • Medical Devices


In summary, the flyback SMPS remains a favored option across numerous power supply applications owing to its advantageous attributes such as high efficiency, compact size, and affordability. Despite its drawbacks such as complexity and potential noise generation, it stands as a dependable and efficient solution for various application scenarios.

You may perform SMPS calculations and obtain figures such as Tmax, frequency, duty cycle, energy per cycle, power, and current in and out by using our online Flyback SMPS calculator. Entering the voltage, transformer inductance value, and transformer VT product will get these values.

Note : Don’t end with comma ( , )

Transformer VT Product
Voltage Primary
Voltage Out
Turns Ratio
Transformer Primary Inductance
Transformer Leakage Inductance
Diode Voltage Drop
Transistor Voltage Drop

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