H-bridge using only n-channel mosfets

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stube40

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I have created an H-bridge PC with 4x floating gate drivers and 4x IGBTs (see attached schematic showing half of h-bridge).

It works very nicely but I would like to replace the IGBTs with n-channel MOSFETs. However, all the H-bridge designs I've seen use n-channels on the low side and p-channels on the high side.

Since my design uses independant galvanically isolated DC-DC converters which effectively provide each of the 4x gate drivers with their own floating supply, is it possible that I can just do a simple straight swap between of the IGBTs with N-channel mosfets?
 

Of course you can. In contrast to your observation, most MOSFET H-bridges (at least for high power) are using N-MOS transistors and working this way.
 

FvM said:
Of course you can. In contrast to your observation, most MOSFET H-bridges (at least for high power) are using N-MOS transistors and working this way.
Click to expand...

That's great. Thanks for your help.
 

Many commercial H-bridge drivers exist and the commercial
market favors all-NMOS power trains for cost so the drivers
accommodate that.

An integrated bridge driver may provide you some niceties
like anti-shoot-through timing that a discrete or SSI solution
would leave as your problem to solve.

All-NMOS schemes will have some minimum switching limits
if they employ a bootstrap cap. This is one thing that a
PMOS high side doesn't require (above-rail gate voltage).
 

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