Atmega328 max pin current absorption

Other Hardware General Electronics
1

Hi all,

I tryed to search on the datasheet of the Atmega328 (Arduino's UNO pic), the maximum value of current absorption but I didn't find it.

I mean, as for the logic ports, there's a value of current that the out pin can absorb while working. I was wondering wich is the limit for the Atmega328.

In my project there are lot of pins initialized as OUTPUT and I want them to absorb something like 60mA (this is for one pin a time, not all of them in the same time; so no 60mA * each pin, just 60mA for a short time on each pin). Is that possible?
Otherwise I'll use some bjts...

2

60 mA for even a short time will very likely damage an output pin on a 328. Absolute maximum current for a pin is 40mA. What are you trying to do? There is a spec for total current for the chip of 200mA as well. Look in Section 28, Electrical Characteristics.

3

After 20mA output voltage degrades. See section 29 and notes that go with the table.

4

S. 29.1 of the datasheet (pg 303) states 40mA per pin is the absolute maximum.

The LGT8F88A that itead studio is using in their iteaduino lite has 8 nmos IO ports that can do double that (80mA)
http://blog.iteadstudio.com/iteaduino-lite-on-indiegogo-now/

5

I know that each pin can provide a maximum of 40mA (if I'm not wrong, this works only for few pins at the same time).
I wanted to know how much it can absorb while is setted as output... Anyway it doesn't matter, I'll use some transistor.

6

I wanted to know how much it can absorb while is setted as output

The real name for this is current sinking not absorption, the answer is the same however 40mA.
If you look at the data sheet again and look for sinking you will see it.

7

Grumpy_Mike:

I wanted to know how much it can absorb while is setted as output

The real name for this is current sinking not absorption, the answer is the same however 40mA.
If you look at the data sheet again and look for sinking you will see it.

That's what I meant. Thanks.

(I wasn't sure that saying: sinking would be understood)

8

Sink (pull a pin low) and Source (drive a pin high), we understand both.

9

Sink:
Current comes from the load and enters in the ATMega
Source:
Current exits from the ATMega and enters in the load

Example:
A LED and his resistor are wired between Vcc and a pin.
To light on the LED, the pin is set to "LOW" ( 0 volts). The current flows through the LED and enters in the pin.
We say : The pin "sink" because the current goes in the pin.

If the LED and his resistor are wired between pin and ground. To light on the LED, the pin is set to "HIGH" (5 Volts)
The current flows from the pin and enters into the LED
We say that the pin "source" because the current goes out from ATMega.

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