AC-DC Power Supply

Examples of AC-DC Converter Circuits Using the Flyback System

Circuit Description


Depending on the location of the IoT sensor device, the power supply may be limited. Depending on the frequency of sensing, the output of wireless communication and other specifications, battery operation may not satisfy the required operation time. In such cases, the simplest solution is to secure a commercial power supply, but you will need to prepare for AC-DC power supply. Generally speaking, external AC-DC adapters are used, and AC-DC power supply modules are purchased and incorporated into the product. However, in order to achieve a balance between performance and cost, designing the optimum power supply for each IoT-sensor device is also an issue to be considered.

MOSFET and SiC-Schottky barrier diodes that apply Toshiba's newest-generation processes are making AC-DC power supplies more efficient. The photocoupler serves to safely transmit feedback signals between the primary and secondary sides of the power supply.

Toshiba has published a switching power supply circuit library to support power supply designs represented by such AC-DC power supplies. In addition, the Reference Design Center publishes examples of the design of various types of power sources, providing design ideas for high-efficiency in various power supply circuits. Both of them can be used free of charge, so please use them as a help in designing the power supply.

Switched Mode Power Supply Library
Easily select the optimal circuit and MOSFETs. Downloads circuit data that can be used in OrCAD®, LTspice® environments.

Reference Design Center
Releasing various reference designs that can be used for end equipment.

The DTMOS series has a super junction structure capable of reducing the resistance of the drift layer, and achieve both low on-resistance and high-speed switching. The π-MOS series adopts the D-MOS (Double Diffusion MOS) structure and the design of double-diffusion structures has been optimized to achieve high efficiency, low noise, and high avalanche capability.

Product Number

(Width×Length×Height mm)

Product Overview

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N-ch, VDSS=500V, ID=18A, RDS(ON)=270mΩ (Max)(@VGS=10V)



N-ch,  VDSS=500V, ID=11.5A, RDS(ON)=340mΩ(Max)(@ VGS=10V)

By realizing low leakage current (Ir) and high surge current capability as well as high reverse voltage ratings and short reverse recovery time (trr), contributes to higher efficiency of switching power supplies.

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VRRM=650V, IF(DC)=4A, IFSM=37A, IR=20μA(MAX), Cj=16pF(Typ.)(@f=1MHz)



VRRM=650V, IF(DC)=4A, IFSM=39A, IR=20μA(MAX), Cj=16pF(Typ.)(@f=1MHz)

Use of photocoupler is effective for isolated power supply in the feedback circuit from the secondary side output to the primary side.

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IC output, BVS=5kVrms, CMH/CML=±10kV/μs(Min)

Other Circuit Description

Sensor Input

Other block diagrams

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