Arduino UNO current limits and Vin


The Arduino Uno datasheet states that the current limitation is 200mA. My question is this , if I use an acdc adapter to externally supply power to the Arduino, can I draw this current from Vin without it being considered within this 200mA limitation?

The reason for this question is that I have applied an LCD shield on the Arduino and Im worried that if it draws around 150mA and since I power a sensor and some other components as well I could pass the limit of 200mA.

Yes, you can draw more than

Keep in mind that there are different current limits depending on which pin you are drawing from. As you guessed, the current limit of the Vin pin is determined by the power supply.

The current limit of the 5V pin is determined by either the voltage regulator that reduces the power supply connected to the barrel jack or Vin to 5 V or else the power supply that is providing 5 V directly via the USB jack. In the case of the voltage regulator, the maximum current is partly dependent on the input voltage. A higher input voltage requires the regulator to drop more voltage and thus it reaches its maximum temperature at a lower current draw. The 3.3V pin is also limited by the current limit of the voltage regulator, but this is not dependent on input voltage because the 3.3 V regulator's input is from the 5 V rail so it has a fixed input voltage.

You also have current limits on the IO pins, which are subjected to per-pin limits (40 mA absolute maximum but the safe limit is around 20 mA) as well as per-port limits for the sum of the current draw on all pins of a given IO port.