You can connect wires from a battery power source here to power the board. As previously mentioned, the voltage on this pin can range from 7V to 12V (recommended) and is regulated down to the 5V the board operates at. VIN pin: The VIN pin is almost the same power connection as the 2.1mm jack (the 2.1mm jack has a diode before the VIN pin connection).

As it uses voltage regulation, you can connect a battery source here to power the board. It then passes through a voltage regulator to bring it down to the 5V needed for operation. 2.1mm jack: The barrel jack input voltage can range from 7V to 12V (recommended). USB: When using a good quality USB power supply, the board receives the 5V needed as a pass-through without regulation. Let’s look at the ways you can supply power to your Arduino Uno in more detail:ġ. The official documentation (see Tech Specs) states that the recommended minimum input voltage for barrel jack and VIN is 7V and the maximum input is 12V. There is the USB port, the 2.1mm center-positive barrel jack, and the VIN header pin. There are several ways that you can power your Arduino Uno. The output of 5V should not change significantly if you stay within the recommended voltage range. If you use a good high-quality power source, the output ratings should be relatively stable. Table 1: Comparison of current handling capabilities of Arduino boards Do these ratings change with different supply voltages?

For the 5V output, you can use a resistor divider to lower the 5V logic signal to a 3.3V logic signal.Ī comparison of maximum I/O (Input/Output) voltage for some of the most popular Arduino boards can be found below in Table 1: Board (see Tech Specs) Additionally, if the 3.3V device’s high output signal has a lower voltage than the lower limits of the input high lower limit, then it is possible that the input will not register the high logic level at its input. While the inputs of Arduino Uno and other 5V devices (see Table 1) can work with 3.3V devices, you might run into some issues with high-speed devices. If you are interested in what the input port protection looks like, you can check “I/O Pin Equivalent Schematic” in “I/O Ports” section in ATmega328P datasheet here. One interesting thing to note is that the absolute maximum input voltage is actually 5V+0.5V due to the input protection diodes. The voltage that you can input or output from any pin on the Arduino Uno is 5V. What are the max voltage ratings of individual pins on my board?Īs we said in the beginning, the pins on the Arduino Uno can output 5V in an either on or pulse width modulation state. Do these ratings change with different supply voltages?.What are the max voltage ratings of individual pins on my board?.

Datasheet arduino uno