Powering 3.3v esp module

Thread Starter

mukams

Joined Apr 12, 2020
19
I am facing a bit issue with voltage regulator 5.5v to 3.3v esp module,I would like to know whats the right capacitor is at Vcc ,I am using AMS1117
The module seems to malfunction after a certain time.I am not using a capacitor at 5v is that the issue.
also which capacitor is suitable for 3.3v
 

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Thread Starter

mukams

Joined Apr 12, 2020
19
esp-12 module gets heated up. At the moment, I am only powering the esp module.
I would like to know which capacitor is suitable as 0.1uf/16v and 10uf 10v is the issue?
 

MisterBill2

Joined Jan 23, 2018
9,853
The capacitors on the input side are often very important for step-down regulators. I am not familiar with this particular module, but some modules will oscillate quite strongly if the input capacitor, especially that 0.1 Mfd capacitor, are not close enough to the input terminals of the module. It may not be the problem but it certainly could be the problem.
 

Thread Starter

mukams

Joined Apr 12, 2020
19
I am designing a circuit for my home automation system. To give a gist, I have a 12V 3.5A supply. I need to operate multiple loads off it. One of the Loads is a ESp12E module.

Esp12e module ----- Max current pull = 350mA. Voltage = 3.3V.

For this purpose, I am using a regulator AMS1117-3.3 Following is my circuit diagram:enter image description here

My Problem is, with this connection, the AMS1117-3.3 regulator is heating up and hence blowing up. I have read the datasheet and it says "Max output current = 1A"
 

ericgibbs

Joined Jan 29, 2010
14,192
Hi mukams,
At 12Vdc in and say 3Vdvc at 0.35A that's ~3Watts.!, that will cook the regulator.

I run my ESP32's from 9Vdc and they still get 'warm'.
Install a 7809 Vreg in the 12V line to the AMS, drop it to 9Vdc for the AMS input

E
 

MisterBill2

Joined Jan 23, 2018
9,853
In addition, add that 0.1mfd capacitor across the INPUT side of the step-down module. Put it close and with short leads. Of course, you do need o be aware of the power dissipated in a linear regulator. Aside from the maximum output current, there is also a maximum device power dissipation specification. and THAT power is what makes the heat. Output current multiplied by the internal voltage drop equals the heating power. Not a small number relative to the size of the package.
 

ElectricSpidey

Joined Dec 2, 2017
1,972
With a 12 volt supply there is no need for a LDO regulator, so I would choose something with a TO220 case for the job, and attach the proper heatsink.

You can also attach a heatsink to your ESP.
 

MisterBill2

Joined Jan 23, 2018
9,853
Certainly filtering out the noise from a switch mode power converter needs more effort than filtering the output of a linear regulator. But it is not that big a deal, and it is not like it needs DC as pure as for a good sound system. Far more efficient, and if batteries are involved, much longer run time and longer battery life. Also smaller lighter, and much less heat.
 

Thread Starter

mukams

Joined Apr 12, 2020
19
I used LM7805 to step down 12V to 5V and then AMS1117A for 3.3v output ,I used capacitor 10nf/16v ,25nf/16v. at the moment esp is running ok .anyone can suggest me better way then this.
 

MisterBill2

Joined Jan 23, 2018
9,853
I used LM7805 to step down 12V to 5V and then AMS1117A for 3.3v output ,I used capacitor 10nf/16v ,25nf/16v. at the moment esp is running ok .anyone can suggest me better way then this.
There are quite a few switch-mode DC to DC power modules available, and in addition there are also mains voltage to 3.3 volt supplies available.
I suggest looking at the DigiKey on line catalog to learn more about the available selections. You may find better prices elsewhere, but this is an honest company and so their catalog is honest as well, and the information is far better than Amazon listings.
 
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