I just launched a kickstarter campaign. I am building an ESP8266_12 breakout board. It has a built in 3.3v regulator, and can even come shipped with the NodeMCU firmware.
Please support and spread the word if you are interested. Thanks!
It doesn't have enough heatsink space for the voltage regulator.
(there are a lot of similar boards that also lack enough heatsink space. ~0.5W ((5-3.3)*.25) is quite a bit of power. Sigh.)
What would you recommend? I have not had any problems with this set up even running at 6.0V. It seems to dissipate heat nicely. I could add a copper heat sink to the board if you think it is needed.
I think it is 6.0V at .250A and needs to dissipate 1.5Watts at full power. The ESP8266 does not constantly consume .250A
E(J) = P(W) × t(s)
1.5X60=90Joules = 21.54 Calories
The specific heat capacity of copper is 0.092 calories per gram per degrees Celsius
Guess I should add a copper heat plain that is 234.16grams or 8.25oz. I know physics dont lie, but I swear I have never had a problem with the mcp1700. I think it can operate a bit above its max specs.
I would at least add as much copper around the regulator as you can possibly fit.
The board I was using apparently burnt itself out and started drawing .5A or so :-(
There are assorted app notes that suggest that ~250 mm^2 of copper (~15*15mm) is a big help (but not too much beyond that.)
If you want to calculate the temperature of the linear voltage regulator package (an example):
P = (6V - 3.3V)*0.25A = 0.675W
T = Rthermal * P + Tambient
Let Rthermal is aprox 50 degC/Watt (ie SOT-89 package soldered to 1 square inch of copper)
T = 50degC/W * 0.675W + 25degC = 58degC
Thermal resistance of the SOT-89 against still air (no heatsink attached) is 330degC/W (=248degC for above example, the package will desolder itself from the wires).
Search for "thermal resistance" of various packages and heatsinks..