ESP8266 Community Forum

- Sat Mar 17, 2018 10:35 am #74664 Hello people!
I'm developing a new project with esp12f on Arduino.
To feed my esp12f I usually use ams1117.
The new design is powered by a 5v switched source and an external backup system with batteries.
In this new project, I want to use the NCP1402 or AAT1217 as voltage regulators for powering the ESP!
Because their regulation range (0.8-5.5v) allows me to enjoy my batteries much better!
According to this table, the maximum that my esp will consume is 170mA.

https://www.letscontrolit.com/wiki/imag ... _usage.jpg


My concern is whether these regulators account for the work.
Will they get very hot?

ps: In my applications they also use a tantalum capacitor of 6v 220uF near the ESP.

- Sat Mar 17, 2018 11:42 am #74667 I took a brief look at both data sheets. The AAT1217 does not seem to be adequate. The AAT1217 looks like it should work as long as you are feeding it with at least 3 volts..

I believe the current values shown in that table are average values and not the peak requirements. I consider 400mA to be an absolute minimum for reliable operation. 500mA being what I use. I tried using quality 250mA linear regulators when I started with the ESP8266 and I would always get unstable operation.

I expected that if I used a higher capacitor value across the ESP I could get away with using a lower capable regulator, but that wasn't the case.

- Sat Mar 17, 2018 12:13 pm #74668 From Expressif's FAQ
https://www.espressif.com/sites/default ... faq_en.pdf

Why does the ESP8266 draws excess current on power-up and does not boot
properly?

The ESP8266 is highly integrated with RF circuits and digital control circuits. When booting,
functions such as RF calibration may draw an appreciable amount of power. The maximum analog
power (instantaneous) may be considered to be 500mA and the digital circuits may draw a peak
current of around 200 mA. The normal operational current is typically around 100 mA, depending on
the application and circuit design.

Therefore, your design must provide for a voltage regulator that can provide 500 mA without
suffering a drop in the output voltage which is outside the operating specifications.

- Sat Mar 17, 2018 1:04 pm #74670

From Expressif's FAQ
https://www.espressif.com/sites/default ... faq_en.pdf

Why does the ESP8266 draws excess current on power-up and does not boot
properly?

The ESP8266 is highly integrated with RF circuits and digital control circuits. When booting,
functions such as RF calibration may draw an appreciable amount of power. The maximum analog
power (instantaneous) may be considered to be 500mA and the digital circuits may draw a peak
current of around 200 mA. The normal operational current is typically around 100 mA, depending on
the application and circuit design.

Therefore, your design must provide for a voltage regulator that can provide 500 mA without
suffering a drop in the output voltage which is outside the operating specifications.

NICE!
look: https://www.ondrovo.com/a/20170207-esp- ... tartup.png

but, maybe AAT1217 hangs on ... what do you think?
I looked better at his datasheet ... I'm confused. I do not quite understand if he regulates the track I said! I'm not sure if he steps down ...