Arduino Nano is a powerful compact size microcontroller. Arduino Nano is based on ATmega328. It is a breadboard friendly board. Like Arduino Uno the Nano board has also a wide range of support for powering this board using different sources. This article will cover Arduino Nano voltage regulator working.
Does Arduino Nano Have a Voltage Regulator
Yes, Arduino Nano has an onboard voltage regulator. Working voltage of Arduino Nano is 5V. To convert any external voltage greater than 5V to Nano working voltage a voltage regulator is used.
Arduino Nano uses the LM1117 voltage regulator. This is the main voltage regulator which converts incoming voltage to 5V which is the working voltage of Arduino Nano boards. Arduino Nano can take power from a variety of sources, including USB, a DC power adapter, or a battery.
Arduino Nano can be powered up using three different ways:
- USB mini cable
- Vin Pin
- 5V Pin
As power coming from USB is a regulated 5V which means it doesn’t need to be regulated first. USB power can be directly given to Arduino peripherals. However, power coming from Vin needs to be regulated first. So, using the on board LM1117 regulator Arduino first regulates this power to 5V.
Lastly Arduino Nano can also be powered up using the 5V pin however it’s not recommended to use this pin as an input source for Nano as slight increase in voltage can damage Arduino board. The 5V pin is connected to the output terminal of the voltage regulator so in case the voltage at the output terminal of the regulator becomes greater than the input terminal this will permanently damage the LM1117 regulator.
Types of Voltage Regulator in Arduino Nano
Arduino Nano has primarily only one main voltage regulator which is LM1117 that outputs regulated 5V. However, Arduino Nano also contains the 3V3 pin which means we also have a secondary voltage regulator which converts the output of LM1117 to 3V3 volts.
The 3V3 pin is connected to the FT232RL UART to USB interface chip. This USB to serial chip takes 5V coming from the USB port or through the output of LM1117 and regulates the 5V to 3V3. Using a 3v3 pin we can power different sensors.
So, we can categorize Arduino Nano voltage regulators in to two categories:
1: LDO LM1117 Voltage Regulator
LM1117 voltage regulator is connected to input coming from Vin pin. Any voltage between 7V-12V can be given to this pin. LM1117 regulates this incoming voltage to 5V and feeds it to Arduino Nano peripherals. It’s recommended to not give voltage more than 9V as most of the voltage is dissipated as heat during conversion to 5V.
Here is a schematic diagram of LM1117 regulator in Arduino Nano:
LM1117 voltage specifications:
| Voltage Regulator | Output Voltage | Max Input Voltage | Max Output Current |
|---|---|---|---|
| LM1117 | 5V | 20V | 800mA |
2: FT232RL LDO 3V3 Voltage Regulator
FT232RL is a USB to serial interface chip using which we can communicate with serial devices such as PCs. This chip takes the 5V from LM1117 and outputs 3V3.
Below image represents the schematic diagram of the FT232RL USB chip which outputs 3V3.
FT232R voltage specifications:
| Voltage Regulator | Output Voltage | Max Input Voltage | Max Output Current |
|---|---|---|---|
| FT232R USB UART | 3.3V | 5.25V | 100mA |
Conclusion
Arduino Nano has onboard voltage regulators which convert input voltage to a regulated 5V. This regulated 5V is fed to the microcontroller and other peripherals. Secondly, the Arduino Nano USB to serial chip also outputs 3V3. For more information related to Arduino Nano voltage regulators read the article.
