Best way to drive Full Bridge FETs

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cupoftea

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Hi,
The attached LTspice and jpeg, is the best way to drive full bridge fets....there is no spurious oncoming, since the top and bottom fets are fed with opposite polarity gate outputs...it doesnt even produce spurious oncoming when "suddenly OFF'd", as you can see in the LTspice.

Why do not more people and App Notes recommend this way?
 

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  • Full bridge gdt.jpg
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  • Full Bridge SMPS_gdt.zip
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..the problem is trying to find gate drive transformers for this. We need 1:1:1 and Lpri >200uH, and Lleak <400nH. And 500vrms isolation.....and >40V.us.

Nothing exists offtheshelf like this.

And the small formers and core sets to wind one ourselves are not available either....
Do you know where we can source?
 

you can get your own coated toroids wound with D.I.W. for the driving side say, and enamel for the o/p side

most makers have bases for these too

this will give you >> 200uH Lpri, and the leakage you seek - the wires are wound bi-filar, or indeed trifilar, with 2x enamel. ( 1 : 1 obviously ).
 
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