Hi everyone. I am a mechanical engineer with a very basic understanding of electronics. The company I work for is small, and we lost our EE a few months ago so all of this falls to me. I was working with some old test equipment (at least 15 years old) this morning and it broke. In a nutshell, the box supplies a variable voltage to our RF circuitry for testing. There is no schematic for the equipment, so after a few hours of tracing out the various connections (it's all built on a breadboard, wires everywhere) I've isolated it to a p-channel MOSFET, VP0120N5. Of course these are obsolete and not available anywhere. So I need to find an alternative.
After googling and reading through other forum posts I think I should be looking at these parameters (I'll include the values for the obsolete part in parenthesis):
Drain-Source Breakdown Voltage (200V)
Continuous Drain Current (-.425A)
Resistance Drain-Source (ON) (15 or 25 ohms, depending on the testing condition)
and of course a p-channel with the same TO-220 package
I'm guessing that for the voltage and current specs I should be looking for a part with at LEAST the above values. But I'm not sure about the resistance. And power dissipation (15W) seems to me to be pretty important too, although maybe that gets worked out between the continuous drain current and drain-source resistance.
I can't seem to find anything close on the Mouser website (seems a tradeoff between current and resistance specs), but maybe I'm just looking in the wrong category. Any suggestions would be appreciated. Thanks so much.
After googling and reading through other forum posts I think I should be looking at these parameters (I'll include the values for the obsolete part in parenthesis):
Drain-Source Breakdown Voltage (200V)
Continuous Drain Current (-.425A)
Resistance Drain-Source (ON) (15 or 25 ohms, depending on the testing condition)
and of course a p-channel with the same TO-220 package
I'm guessing that for the voltage and current specs I should be looking for a part with at LEAST the above values. But I'm not sure about the resistance. And power dissipation (15W) seems to me to be pretty important too, although maybe that gets worked out between the continuous drain current and drain-source resistance.
I can't seem to find anything close on the Mouser website (seems a tradeoff between current and resistance specs), but maybe I'm just looking in the wrong category. Any suggestions would be appreciated. Thanks so much.