user39663: I have a arduino set below:
pinMode(1,OUTPUT);
digitalWrite(1,LOW);

Now, I am expecting 1.2mA current flow through the pin that is set as output. Is that accepted? If so, what it the max current a pin can sink?
The current comes from a pul up resistor on the line
note: I can't protect it with a diode.

user30005: 
can arduino on output mode sink current?

yes.

from the arduno docs:

the datasheet for the particular device is the best place for that answer.

user4143: Yes it can. This blog post of mine will help to explain it.
In short:

It’s all so simple now, isn’t it? The output pin is just like a switch that either connects it to 5V or to ground.


user39663: Ok, I just found it.
from the arduno docs: 
Atmega pins set aa output can source (provide positive current) or sink (provide negative current) up to 40 mA (milliamps) of current to other devices/circuits.

39663: <p>I have a arduino set below:</p>

<pre><code>pinMode(1,OUTPUT);
digitalWrite(1,LOW);
</code></pre>

<p>Now, I am expecting 1.2mA current flow through the pin that is set as output. Is that accepted? If so, what it the max current a pin can sink?</p>

<p>The current comes from a pul up resistor on the line</p>

<p>note: I can't protect it with a diode.</p>
 30005: <blockquote>
  <p>can arduino on output mode sink current?</p>
</blockquote>

<p>yes.</p>

<blockquote>
  <p>from the arduno docs:</p>
</blockquote>

<p>the datasheet for the particular device is the best place for that answer.</p>
 4143: <p>Yes it can. <a href="https://hackingmajenkoblog.wordpress.com/2017/03/20/what-exactly-is-a-gpio-pin/" rel="nofollow noreferrer">This blog post of mine will help to explain it</a>.</p>

<p>In short:</p>

<blockquote>
  <p>It’s all so simple now, isn’t it? The output pin is just like a switch that either connects it to 5V or to ground.</p>
</blockquote>
 39663: <p>Ok, I just found it.</p>

<p>from the arduno docs: </p>

<p>Atmega pins set aa output can source (provide positive current) or sink (provide negative current) up to 40 mA (milliamps) of current to other devices/circuits.</p>
