2nd question here. I designed a simple H-bridge circuit using 2 N-channel and 2 P-channel SOT23 mosfets which are rated to 4.0A (ao3400 and ao3401). I would prefer a good H bridge chip. But I have three problems. Being a JLCPCB guy, I have a really really crappy component searching tool at my disposal. This makes searching a bit difficult. Now I also tried searching on sites like mouser and farnell.
This leads to the 2nd problem. Every half decent H-bridge chip I can find is godless expensive. I mean €10+ per chip. That is why I chose for separate mosfets. The one affordable chip I could find was the the L298 in THT multiwatt package which is not really an option for me.
And problem 3 is the massive shortages on these kind of chips.
Can anybody recommend me an SMD H-bridge chip which can supply 3A on a single channel?
I’ve used TI’s DRV8212s in the past for low-current applications.
They are up to 4A, dirt cheap on Digikey (<$0.60 in any sane quantities), reasonable at JLCPCB ($0.81 as extended part), SMD so super easy to rework if needed…
If you want more power (DRV8212s top out around ~10V/4A), Monolithic’s stuff is pretty good as well (MP6519GQ/MP6619GQ), that’s my default go-to driver, typically I prefer 24V as my motor rail, 28V/5A can do a fair amount of moving around… <$3 on Digikey, but not present at JLCPCB’s P&P machines.
I highly recommend getting a Miniware MHP30. It’s a 3x3 cm (1.2x1.2") hotplate that allow you to easily reflow a single chip on a PCB. Very easy to work with and stash away since it’s so tiny.
I looked into hot plate soldering and it looks really nice tbh. It also looks as a fast process. Usually I start with soldering half of the pads, than I solder in the components and I finish with soldering the remaining pads. But with a hot plate you can just apply paste everywhere, place the components and wait a few minutes…
Perhaps I can make stencils using a cutting plotter like our cameo 4, that would be neat.
I also found a video who made one himself using a PCB. It seems relative easy to do.
For prototyping with larger components, you can just slather paste and then nudge the parts around while the solder is liquid and most blobs will “snap” to the pads. Even SOIC/QFPs will do this if you put a judicious amount of paste. Any excess can usually be cleared by retouching with an iron tip. It does get trickier with fine pitch parts, though.
I don’t have the tools for those chips with pads on the bottom.