Can LDMOS handle the current in both direction, D->s and S->D ?

[pleezer]

Hi.

I'm trying to use an NLDMOS in tsmc 0.25um to implement Flyback converter.

I know an LDMOS is not symmetric device, which means the source and drain sides are fixed.

The question is this. Is it possible the current in LDMOS flow through its 'Source to Drain' (not Drain to Source) direction?

The source is connected to its ground.

Thank you for reading it!

 

[FvM]

A MOSFET will be always able to conduct current in both directions. I guess you want to ask about the ability to block Vds in both directions? It will be usually dwarted by a source to bulk connection and forward bias of the BD junction.

 

[selix]

I have the same question with the poster, as to specific LDMOS technology, f.x isolated LDMOS in HV-CMOS process, when Vs>Vd and Bulk is connected to Source, I wonder if the parasitic BJT (between bulk, drain, psubstrate) may conduct and cause problems.