Hello,
I am trying to replace MRF1K50H with MRFX1K80NR5 and having strange problem. I cannot set idle current at 1A level. I slowly increase bias voltage and when idle current is around 0.8A it starts growing by itself rapidly and can reach very high values. I turn off power to transistor to prevent it from damage.
What could be causing this?
I know that MRFX1K80NR5 does not have flanges so I carefully attached transistor to copper plate with water cooling (using Liquid Ultra as thermal paste) to make sure it will have adequate cooling. Is there something else I am missing?
Thank you,
Nick NA3M