I Quote from the Fairchild sheet I enclosed...
N-Channel Logic Level Enhancement Mode Field Effect Transistor
However had you read the next 3 pages and paid attention to Vgth
you would have noted that .8V was enough to cause a 1mA current to flow, and had you looked at the graph on page 3 top left side of the page you would have seen that 2.5V Vg @ 1V Vds was enough to cause 400 500 mA to flow... Clearly a good part for a 150 mA load... from 3V3 logic too.
The mistake iis easy enough to make If your electronics knowledge is spotty... The rest of the data sheet is quite clear however. That's why there are characteristic curves for the device on the other pages.
I was Very surprised that you chose to ignore the "Logic Level" Statement at the top of the page. And Yes certainly a ULN2003 will work, with 6 unused sections and some other drawbacks as well... Vcesat
is about 1.5V Vs 40 mV for the Mosfet... @ 500 mA for the '2003 and 150 mA for the BSS138 so they aren't quite in the same class... The '2003 was originally developed as a Print head driver for the old "Dot Matrix" printers. Many years ago... Thus only 7 drivers, the eighth pin was part of the character spacing. and not used except in a few of the real "Letter Quality" printers Panasonic KXP1135 is one and I still have one stored in my garage that is nearly new... One of the very few besides the Okidata model 82 that could do 7 part NCR forms.
Like C and C++ reading a data sheet requires that you understand what you read... at least a little.
If I was too hard on anyone I apologize. I read the data sheet carefully before I said it would work fine. The comments about the other Fet and the subsequent recommendations for "Driver IC's" were really out there
Much like using a 10 kiloton bomb just to kill the flys in the back yard, Workable but hardly desirable.
I have been doing Engineering for about 30 years total and I WILL NEVER make a recommendation that won't work... or for that matter one I haven't already done.
I would be really ashamed of myself for telling someone something that was clearly wrong.
If I ever say I don't know... it's because I couldn't get the information or figure out how to solve the question at hand...
Some questions I don't even bother with... because there are too many "Experts" involved already.
If there are any other questions... pm me, i Will answer as quickly as I see the email notification. I hope this helps... a little