What transistor should I use?

I did an audio amplifier, but the joy was short.
At the final stage it has an IR2110 driver.

I used the IRF840 and I noticed they're getting hot enough.Ddson=0.8ohms.
In is without heat sink and I do not have Gate resistor.
Then I replaced with sk2134 Rdson=0.4ohms.
And heat less, but they still get warm.

IRFP150 has Rdson=50mohms, but it has 100V maximum.
I did not understand why at next, IRFP240 Rdson does not double but increases unexpectedly.

If the power source used for the amplifier (step-up) is faulty It can give up to 200V(+/-100V).

 

Hello,

What current should be expected at the Rdson?
Have look at these fets:
https://www.digikey.com/products/en...t=0&page=1&quantity=0&ptm=0&fid=0&pageSize=25

Bertus

 

IRFP250, IRFP260 seem to be a good choice.