How to simulate MOSFET output stage SOA curves at LTSpice?

[danny92]

Hi everyone,

I'm doing a project with a class AB/B power amplifier with MOSFET output and I'm thinking about incorporating a VI limiter to the output devices. It was told me that the curves can be made with the help of LTSpice, but I don't know the commands I should use. Can someone help me here?

Best regards,
Daniel

 

[fas42]

Haven't tried it myself, but if you join the Yahoo LTspice users group there is at least one example there of doing this sort of thing, http://groups.yahoo.com/neo/groups/LTspice/files/%20Examples/Apps/Curvetrace_SOA/.

 

[jazbo8]

You need to join the Yahoo Groups to read the threads from the above post. But it is simply adding a trace to your characteristic curves, e.g., if the maximum dissipation is 10W, then add a trace with y=10/x, where x is the voltage.