I’m designing my first PCB and having trouble choosing a good combination of physical terminal block and footprint. This seems like a very basic thing everyone must do, so I’m puzzled.
Physically, I want something that I can buy cheaply (in small quantities) through say digikey, that handles my current and wire gauge (I need a 2-pin >=10A and a couple 3-pins >=5A, I think 16 AWG on both), and that isn’t too large (the 3.5mm pitch sounds good). search. The Adam Tech EBWA-*-A jumped out, or the On Shore Technology, or the Amphenol Anytek. The GCT one is cheapest but annoyingly doesn’t seem to give any dimensions other than the pitch.
Footprint-wise (and ideally 3D model wise but I guess that’s optional)…
- I was expecting to just find the standard library had footprints that would do for most/all of these. Am I missing them? I filtered for
3.5and only saw the following:TerminalBlock_4UCon_1x02_P3.50mm_Horizontalwould be fine if I could buy the part, but 4UCon stuff doesn’t look available through digikey, and neither does anything that looks close enough that I think the footprint would work. E.g. compared to the Adam Tech one, different overall width and depth, round? vs…oblong/rectangular? pins)TerminalBlock_Phoenix_PT-1,5-3-3.5-H_1x02_P3.50mm_Horizontal…actually on like fifth look I think this the same as digikey 1984617. Bit more expensive than the others but possible then.
- I tried downloading a footprint for that Adam Tech one through digikey. But the datasheet says the pins are 0.90mm wide and the footprint’s pad hole is 0.889 mm diameter. If I understand correctly, JLCPCB says their pad holes have a tolerance of +0.13mm/-0.08mm, so I could end up with a 0.809mm hole that I don’t think I could cram the 0.90mm-wide pins into. Are these footprints trustworthy?
I might just go with that safe-looking Phoenix part, or I might start from the Adam Tech footprint and expand the hole size, but I’m new to this and wanted to make sure I wasn’t missing something first. I’m afraid of going through N rounds before I get a good board on what should be a simple project.