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

PostPosted: Sat Nov 07, 2015 12:54 am
by jertcen
shoelessone wrote: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?


Here is something to read, although I'm sure there are many other and/or better sources of info out there:
http://www.analog.com/media/en/training ... MT-101.pdf

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

PostPosted: Sat Nov 07, 2015 6:38 am
by Barnabybear
shoelessone wrote: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?


Hi, the two capacitors after the regulator are for two different reasons (as close to the ESP power pins as possable).
100uF is to act as a store or reserve to give the regulator time to catch up with the demand when the ESP transmits. This is normaly an electrolitic type and only needs to be 6 or 10V rated.
0.1uF is to remove any spikes or noise on the supply that may affect the ESP. This is normaly a ceramic or tantalum type.

The regulator manufacturer may specify a capacitor before. This is usally an electrolitic type and again acts as a reserve when the regulator demand increases.