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AC-DC Resonant Full-Bridge Power Supplies

Since full-bridge power supplies provide higher efficiency than half-bridge circuits, they are mainly used for large-capacity applications (with over 1-kW capacity). Full-bridge power supplies require MOSFETs with high-speed switching performance or those with a diode having short reverse recovery time (trr). Toshiba offers 600- to 650-V MOSFETs that combine both of these characteristics.

Block Diagram

Click on the colored blocks to view recommended products.

フルブリッジ型AC-DC電源の回路例

Blocking Diode PFC MOSFET PFC Controller ICs Main Switch MOSFET Photocoupler Gate Driver Rectification MOSFET Oring MOSFET

Documents

Whitepaper

Whitepaper
Name Outline Date of issue
Describes the features of the DTMOSV series and the improvements from the previous series 9/2017

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  • DTMOS Applications (Noise Reduction)
Describes the mechanism of noise generation and noise reduction techniques 9/2017 coming soon

Application Note

Application note
Name outline Date of issue
Describes planar, trench and super-junction power MOSFETs 11/2016
Describes the absolute maximum ratings, thermal impedance and safe operating area of power MOSFETs 11/2016
Describes electrical characteristics shown in datasheets 11/2016
Describes how to select power MOSFETs, temperature characteristics, the impacts of wires and parasitic oscillation, avalanche ruggedness, snubber circuits and so on 11/2016
Describes thermal equivalent circuits, examples of channel temperature calculation and considerations for heatsink attachment 2/2017
Describes the guidelines for the design of a gate driver circuit for MOSFET switching applications and presents examples of gate driver circuits 8/2017

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Describes the oscillation mechanism of MOSFETs for switching applications 8/2017

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Video

Video List
When you click on a thumbnail below, you can view the video.

"Introducing the U-MOSⅨ-H Series: Existing video"

Evaluates the performance of the U-MOSIX-H trench MOS series in an isolated DC-DC/DC converter and compares it with products from other companies

Date: 1-Sep-2017

Time: 02:16

    DTMOS
    DTMOS

"DTMOS"

Describes the features of DTMOS

  • Circuit Overview

    Although full-bridge AC-DC power supplies have a complex circuit configuration, low-voltage devices can be used to build them.

    Since full-bridge AC-DC power supplies exhibit high efficiency, they are used for 300-W and higher-capacity power supply applications.

    The circuit on the primary side of a transformer is comprised of Q1 to Q4, their parasitic diodes, and an inductor (L). The current flows change as shown in the figure according to the "on" and "off" states of the transistors.

    Timing 

    0 to t1:Q1,Q3:ON    Q2,Q4:OFF

    t1 to t2:Q1,Q3:OFF

    t2 to t3:Q1,Q3:OFF    Q2,Q4:ON

    t3 to t4:Q2,Q4:OFF

 *Click the headline to open it

  • Operation

    1. Q1/Q3 ON

    Q1 and Q3 are turned on. As a result, Vs is applied across the primary winding of the transformer Np.
    At the same time, the energy stored in the primary winding is transferred to the secondary winding. Since the polarity of this voltage is positive, an electric current flows through D1 and L, charging C.

    2. Q1/Q3 OFF

    When Q1 and Q3 are turned off, the energy stored in the reactor LD is flowing a load current in the secondary side.

    3. Q2/Q4 ON

    Q2 and Q4 are turned on. As a result, Vs is applied across the primary winding of the transformer Np.
    At the same time, the energy stored in the primary winding is transferred to the secondary winding. Since the polarity of this voltage is opposite to that at Step 1, a current flows through D2 and L, charging C.

    4. Q2/Q4 OFF

    When Q2 and Q4 are turned off, the energy stored in the reactor LD is flowing a load current in the secondary side.

    The output voltage is approximated as follows:

    t(on): Cycle period minus dead time,
    T: Cycle period, Np: Primary winding, Ns: Secondary winding (Ns1=Ns2=Ns), Vs>>Vds, Vf

    VOUT=[Vs x (Ns/Np) ]x ( 2xt(ON)/T)



 *Click the headline to open it

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·Before creating and producing designs and using, customers must also refer to and comply with the latest versions of all relevant TOSHIBA information and the instructions for the application that Product will be used with or for.