M.Tech (Industrial Electronics, NIT-Surat), Gate, B.E. (Electrical Engineering., VNSGU-Surat).
Experience: 13 Years.
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Buck Converter (Step-down converter):
DC-DC Converter
DC Chopper.
Switch=MOSFET or IGBT
Application:
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Circuit Diagram:
Two mode:
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Circuit Diagram:
Two mode:
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Buck Converter (filter):
L and C filter purpose. To reduce Size, f increases
Vo assumed to be constant
Continuous conduction mode: IL is continuous.
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Circuit Operation when switch is on 0<t<dt:
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Circuit Operation when switch is off (1-d)t<t<dTs:
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Operation:
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Current ripple:
Continuous Conduction:
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Volt. ripple:
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Buck Converter Design:
Power supplies with high current at low voltage are required. Design a buck converter has an input voltage of 15V and an output voltage of 4.7V. The output current varies between 10 and 25A at different loads. The output voltage ripple must not exceed 1%
Specify the minimum inductor value such that the converter is always operated in continuous conduction mode and the peak-to-peak inductor current does not exceed 20% of the average value for all operating condition.
Determine the required rms current rating of the inductor.
Determine the value of capacitor such that the output voltage ripple is less than 1%.
Select a suitable semiconductor device for the switch (please specify the key parameters of your chosen device) and estimate the maximum power loss of the device during operation. (You don’t need to consider diode in the exercise)