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By lucasromeiro
#73610
rudy wrote:I often will need 5 volts in my designs so I use a switcher to go from 12 to 5. Then I use a linear regulator to provide the 3.3 volts. If I don't need an intermediate voltage then I have also used switchers to go directly to 3.3 volts. But make sure that whatever approach you use that the devices are rated for at least 1/2 an amp at 3.3 volts.

With your linear regulator it has to dissipate three times the power that the ESP module is using. Yes it will get hot.

https://www.aliexpress.com/item/3pcs-1A ... 53201.html



Thanks for the answer!
I do not understand what you mean by"But make sure that whatever approach you use that the devices are rated for at least 1/2 an amp at 3.3 volts."
In my project I need 5v. But the important part is that it has 3.3v and does not get too hot.
Is it interesting to use an LD1086 regulator to convert from 12v to 5v and then use a 1117 regulator to convert to 3.3v?
I found the link you sent me very interesting! is really small! I could absorb this circuit for my board, copy the components to my circuit ... is it a switcher regulator in the link ?? I read that switcher controllers are heat efficient but generate noise and do not recommend using. can you explain more?

Tks !!
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By lucasromeiro
#73611
trackerj wrote:It's way better and more efficient to use a switchmode regulator like this one:
Synchronous step-down DC-DC converter


Image
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Hello! Thanks for the answer! :D :D
Is it interesting to use an LD1086 regulator to convert from 12v to 5v and then use the 1117 regulator to convert to 3.3v?
Nice picture, is really small! I could absorb this circuit for my board, copy the components to my circuit ... is it a switcher regulator in the link ?? I read that switcher controllers are heat efficient but generate noise and do not recommend using. can you explain more?

Tks !!
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By eriksl
#73644 The lm137 or lm337 is surely not a switching regulator. Don't use it!

Use something like this, a switching buck (step-down) converter to lower the voltage from 12 V (or higher) to 5 V.

https://www.ebay.com/itm/10pcs-Mini-DC- ... 2749.l2648

Then use a lineair regulator to bring the voltage further down from 5 V to 3.3 V. This will guarantee the cleanest supply, little ripple caused by the switching converter. The LM3940 is specially designed for this purpose, it will always output exactly 3.3 V.
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By btidey
#73648 It is OK to use the 2 stage method if you want very clean supply, particularly if using the ADC.

However, I have had zero problems from many modules powered from mini buck converters direct to 3.3V. They typically have less than 50mV residual noise and this does not affect the operation of the device.

It is good practice with either approach to include decoupling capacitor(s) as close to the ESP module as possible.