Why flyback diode is preferred over fwd body diode of Mosfet in case of H-Bridge? Can fwd body diode of MOSFET can serve the purpose of flyback diode?
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Wiki says it better than me: -
Body diodes may be utilized as freewheeling diodes for inductive loads in configurations such as H-bridge or half bridge. While these diodes usually have rather high forward voltage drop, they can handle large currents and are sufficient in many applications, reducing part count, and thus, device cost and board space.
answered May 22, 2014 at 10:56
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\$\begingroup\$ If i dont use flyback diode then it result into heating of MOSFET , if fwd body diode is enough then i think that heating problem will not be there. But if i use flyback diode then power disspation across MOSFET decreases as compare to the first case. As rating for the fwd body diode is same as the MOSFET as per my knowledge. \$\endgroup\$ Commented May 22, 2014 at 11:36
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\$\begingroup\$ The heat (or excess energy from the inductive elements in the H bridge load) has to go somewhere and be turned into heat or stored in your power supply capacitor to be turned into heat at some later point. There is no escaping the heat issue. The question is do you want it turned into heat by your mosfet or by a flyback diode? \$\endgroup\$– Andy akaCommented May 22, 2014 at 11:47