Replacement FET (200 Vds, 30A)

Hi all, I need to pick a replacement for a 200V Vds, ~30A (it can be less) FET in a TO-220 pack. NTP30N20 (spec sheet here.)

formatting link

The FET is being switched on from 5V (Vgs) (Looking at the data sheet a fet that turned on a bit sooner would be fine.) There are several and I'd just like your best guess as to which will be around the longest. My typical way of picking is to enter the parameter I want into Digikey and then sort by quantity, and pick one near the top.

Here's my list and DK search results.

formatting link

NXP PSMN070-200p PHP20NQ20T PHP33NQ20T

STMicro STP30NF20 STF40NF20

Fairchild FQP32N20

And others.

I'm leaning towards the PHP33NQ20T (which at least turns on at 5V)

formatting link

Thanks

George H.

Reply to
George Herold
Loading thread data ...

I'd shoot for the lowest Qg at 5V.

Cheers

Reply to
Martin Riddle

Thanks Martin, I ordered Fairchild, as well as the NXP above. I figure both will work, And I'll have two replacements. I didn't design the circuit. So I only know it sorta. The important part is when it shut's off the polarizing current in an Earth's Field NMR apparatus. A big air coil made with litz wire, R~10 ohms maybe 1000 turns, I'd have to look up the inductance. maximum current 3A for ~20 seconds. There's damping network, Zener, diode and resistors. That soaks up most of the back emf. And (I think)* that as long as it turns off in less than ~1/4 cycle of the resonant frequency (~3kHz) then the spins don't have enough time to "follow the field" as it decays, and they remain polarized.

George H.

*there are provisions in the circuit to change a damping resistor, and the turn off time. I'll have to check it out at the same time as I'm swapping fets.
Reply to
George Herold

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.