Current for Arduino Mega's 3V3 pin

[jordiruhi]

Hello I'd like to know what is the current that the 3.3V pin of the Arduino Mega 2560 can handle.

I've looked at Arduino's webpage and it specifies that the maximum current is 50 mA
Arduino Mega 2560 Rev3 — Arduino Official Store

But then i looked at the datasheet and the power tree specifies that the current is 150 mA
https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwjQyKiwg8aFAxWpcKQEHSU2DdEQFnoECCUQAQ&url=https%3A%2F%2Fdocs.arduino.cc%2Fresources%2Fdatasheets%2FA000067-datasheet.pdf&usg=AOvVaw0F42cuXrNWgmF0KgNGiU89&opi=89978449

What am i missing

[DrDiettrich]

@jordiruhi

What am i missing

Possible current depends on the 5V supply. Worst case is 5V from 17V, what leaves not much current for the 5V output and still less for the derived 3.3V. If instead the 5V come from USB or a 5V power supply then the 3.3V regulator allows for much more current.

As a rule of thumb an Arduino board should not be used as a power supply, except for a few LED or low power sensors.

[jim-p]

@jordiruhi

What am i missing

Nothing.
It's a documentation error. Which is correct who knows. However, pinout diagram also states 50mA. So it's two to one against the 150mA. Safe bet is 50mA.

[JohnLincoln]

The voltage regulator fitted is type LP2985-33DBVR.

The manufacturer's datasheet calls it a 150mA, Low-Noise, Low-Dropout Regulator with shutdown.
The 150mA limit will be dependant on it having adequate heatsinking from the PCB.

[Wawa]

Long standing error in the Uno/Mega documentation, carried over from the first types where the 3.3volt was taken from the USB chip. All Uno R3 and Mega boards now have a dedicated 3.3volt/150mA regulator, that takes it's power from the 5volt rail. Small boards, like the classic Nano v3, still take 3.3volt from the USB chip, with that 50mA limit.
Leo..