Is this an acceptable replacement part...? N Channel FET

I have built up my circuit for driving a number of LEDs (about 20) using a PH7030L N channel TrenchMOS on the recommendation of folks on this forum. I'm now building my BOM and have realised that this part is discontinued wherever I look. Would this be an acceptable replacement do you think? Or are there any better parts to do the job?



The old MOSFET is rated at 60A drain current. The new one is rated for 5A. Will 5A be enough?

It's only around 20 LEDs so should be more than enough...??

Its also rated for only 20V, has double the on-resistance...

Note current ratings are not interesting, power ratings and on-resistance are what you look to to size a MOSFET, the current rating is the max power rating in disguise (and assuming infinite heatsink too, so its not normally realistic).

Calculate the actual power you'll dissipate using I-squared-R. Compare to what the device and heatsinking can take. This will help you choose the on-resistance wisely.

Pick a voltage rating double your circuit voltage for good measure - but picking a very high voltage rated device isn't wise, the on-resistance is necessarily higher for high voltage devices, all else being equal.

Anyway there are many thousands of logic-level MOSFETs out there to choose from, set you parameters and do a parametric search on the website of the electronics supplier of choice...

Sorry Mark I'm a bit lost here... There are so many variables! Can you offer any advice to help limit the choice? I'm only using it to have an arduino 5v output drive 20 or so LEDs in an automotive environment..

Ok how about this bad boy?

So 55V (automotive qualified is good to have), logic level, but what current? 20 LEDs doesn't mean anything, I own LEDs that are rated for 3A for instance, some are 1A, some 350mA, some 60mA, some 20mA...

What heatsinking do you have or want to have or not have?

Ah sorry, these are little 900mcd plcc-2 20ma LEDs just used for instrument back lighting, ideally dont want much heat if possible!

20 x 20mA = 0.4A, so a 2N2222 would actually do the job, for a MOSFET you'd like the on-resistance to be less than 1 ohm, not an exacting requirement, many are less than 0.1 ohm which is only 16mW dissipation at 0.4A.

Just be sure its logic level and has a reasonable voltage rating to handle spikes on the supply. The one in #5 is clearly up to the task.