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Re: New to esp8266/Eagle - custom PCB - special consideratio

PostPosted: Wed Nov 04, 2015 9:48 pm
by GrahamH
I went to Digikey and entered 100 uF and surface mount in their component selector and came up with ten different 100 uF caps, 6.3 V or higher rating in the range of $ 0.81 to $ 1.20. Size 1206 or 1210.
Try:
1276-1782-1-ND by Samsung
490-7217-1-ND by Murata

Not $4.00, not big.

--- Graham

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Re: New to esp8266/Eagle - custom PCB - special consideratio

PostPosted: Wed Nov 04, 2015 9:56 pm
by jra
I built this board from Osh Park https://oshpark.com/shared_projects/9CsYq2PY using the following capacitors that I already had in my parts bin:

10uf 16V tantalum https://www.mouser.com/Search/ProductDe ... 91B106K016 on the input
47uf 6V tantalum https://www.mouser.com/Search/ProductDe ... 91B476M006 on the output

I've only been running it for a couple of weeks now but haven't seen any stability problems. Mouser also has the following 100uf 6V tantalum for $0.23 quantity 1 in a 1211/3528 case

http://www.mouser.com/search/ProductDet ... 930J107MBA

Re: New to esp8266/Eagle - custom PCB - special consideratio

PostPosted: Thu Nov 05, 2015 9:26 am
by shoelessone
jra wrote:I built this board from Osh Park https://oshpark.com/shared_projects/9CsYq2PY using the following...


Beautiful!

Thank you for the link, $0.23 is great! I certainly had no problems going with the 100uF cap, so if I can afford it and get the parts I'll do that! I think maybe part of my problem before is that I was searching for 0805 size parts or something (I don't totally "get" the SMD sizes yet, but I've since googled and read that 1206 is a great, I'm not sure what 1211 is which that part seems to be but I'll look into it!).

Martin, I also ordered those capacitors you linked to, which were also great (I think the test/breakout board has that same part, maybe?), but I'm unsure if they will make it hear on time.

Also, I've read somewhere that ceramic capacitors are the most preferable, but I don't have any idea how much that matters for this type of application. I'm guessing not a TON or you guys would have recommended them specifically :)

Re: New to esp8266/Eagle - custom PCB - special consideratio

PostPosted: Sat Nov 07, 2015 12:32 am
by shoelessone
OK, so, is there some documentation regarding "best practices" and the regulators around the regulator?

I looked at the data sheet and they have a 10uF before the regulator and 100uF after.

I'm wondering what I should do. 100uF after and .1uF before? 100uF and .1uF before and after?

I feel like i"m just randomly putting capacitors everywhere...

Thoughts?