switched capacitor converter with continuous conversion ratio resonant switched capacitor converter

Download Switched Capacitor Converter with continuous conversion ratio Resonant Switched Capacitor Converter

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  • Switched Capacitor Converter with

    continuous conversion ratio

    Mert Turhan

    20.06.2017

  • DC/DC converter topologies 1

    ► Capacitive Converter ► Inductive Converter ► Linear Regulator

  • Advantages of Switched Capacitor Converter (SCC)

    • No magnetic elements − No inductive switching losses − Can be fabricated as IC

    • High power density

    2

    0

    20

    40

    60

    80

    100

    120

    140

    160

    Energy Density (µJ/mm2)

    Energy density of an inductor and a capacitor

    Inductor (10µH Coilcraft SMT)

    Capacitor (1µF T-Y Ceramic)

    149

    ~1

  • Integration 3

    ► Inductive ► Capacitive

    Source: V. Wai Shan Ng ,'Switched Capacitor DC-DC Converter: Superior where the Buck Converter has Dominated', PhD Berkely

    DC-DC step-down inductor based with the inductor marked. Vin=5V-23V, Vout=1V-17V and Iout=3A

    DC-DC step-down switched-capacitor converter (SCC) Vin=7.5V-13V, Vout=1V and Iout=1A

  • Why not SCC?

    • Output voltage regulation is tied to efficiency

    • Not suited for high current/power

    • Lots of switches and gate driver

    • Voltage balancing for many caps

    • Current stress

    4

  • Voltage Conversion for Dickson Converter 5

    3:1 Dickson Converter First phase, odd switches are open

    Second phase, even switches are open

  • Step-up Switched Capacitor Converter 6

  • Resonant Switched Capacitor Converter

    • Even the efficiency increases, the output voltage is discrete and is tied to the load

    7

    60

    65

    70

    75

    80

    85

    90

    95

    100

    0,3 0,8 1,3 1,8

    Ef fi

    ci en

    cy (

    % )

    Output Current (A)

    Conventional SCC without Lr

    r=20mΩ r=50mΩ

    Resonant SCC with Lr r=20mΩ

    r=50mΩ

    1,5

    1,7

    1,9

    2,1

    2,3

    2,5

    0,3 0,8 1,3 1,8 O

    u tp

    u t

    V o

    lt ag

    e (V

    ) Output Current (A)

    Conventional SCC without Lr

    r=20mΩ r=50mΩ

    Resonant SCC with Lr r=20mΩ

    r=50mΩ

  • SCC with Continuous Conversion Ratio

    8

  • Derivation of SCC with Continuous Conversion Ratio 9

  • The step-up SCC 10

    • To connect the capacitor cells in order to increase the conversion ratio

  • Step-up SCC with 2 SCs 11

    Conversion Ratio versus duty cycle (δ)

  • Operation of the step-up SCC

    12

  • Efficiency

    Parameters

    C1, C3 0.1µF

    C2, C4 10µF

    L 2.2µH

    fsw 215kHz

    Vin 20-40V

    Pout 100W

    13

  • Loss distribution of the converter

    14

  • Size comparision

    • Four Level Boost Converter (FLBC) Balancing circuit was not taken into account

    15

    • SCQRC

    %12 less

  • Conclusions

    • Capacitors may be used in order to minimize the size of the inductor

    • There is no unbalancing problem at charge pump topoplogy

    • Capacitor cells may be used to increase conversion ratio without extra loss

    16

  • Switched Capacitor Converter with

    continuous conversion ratio

    Mert Turhan m.turhan@tue.nl

    20.06.2017

  • 18

    Source: Asmarashid Bin Ponniran, Koji Orikawa, and Junichi Itoh,

    Minimum Flying Capacitor for N-Level Capacitor

    DC/DC Boost Converter

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