Advanced Member level 4
I get what the gate driver transformer does and I basically get the half bridge.
But why is one end of the secondary coil for the top mosfet connected to -120VDC? Shouldn't it be connected directly to -120VDC as with the secondary coil for the bottom mosfet?
Why connect the two output pins of the UCC.... chips together at both end of a single primary coil on the gate driver tranformer? Why not, for example, have two seperate gate driver transformer (1:1) aqnd connect each UCC... chip to these two independant primary coils and then each individual mosfet gate to the independant secondary coils?
I do understand that the current through the primary coil will flow in different directions depedning on which of the UCC... chips is on. Presumeably the output pins can sink current as well as source it.
I also think I understand why the connections for the bottom mosfet to its gate driver secondary are reversed, i.e. so that both mosfet don't activate at the same time.
But why do it in this complicated manner? Why not just two seperate gate driver transformers?