Enter the resistance, temperature, and bandwidth into the calculator to determine the resistor noise voltage. The calculator will evaluate the noise voltage in nanovolts per square root hertz (nV/√Hz).

Resistor Noise Voltage Formula

The following formula is used to calculate the resistor noise voltage:

NV = √(4 * k * T * R * B)

Variables:

  • NV is the noise voltage (nV/√Hz)
  • k is the Boltzmann constant (1.380649e-23 J/K)
  • T is the absolute temperature (Kelvin)
  • R is the resistance (ohms)
  • B is the bandwidth (Hz)

To calculate the resistor noise voltage, multiply the Boltzmann constant by the absolute temperature and resistance, then multiply by the bandwidth, and finally take the square root of the product.

What is Resistor Noise Voltage?

Resistor noise voltage, also known as thermal noise or Johnson-Nyquist noise, is the electrical noise generated by the thermal agitation of charge carriers (usually electrons) inside an electrical conductor at equilibrium, which happens without any applied voltage. It is a fundamental noise that depends on the temperature and resistance of the material and is present in all resistors.

How to Calculate Resistor Noise Voltage?

The following steps outline how to calculate the Resistor Noise Voltage.

  1. First, determine the resistance (R) in ohms.
  2. Next, determine the absolute temperature (T) in Kelvin.
  3. Next, determine the bandwidth (B) in Hertz (Hz).
  4. Next, gather the formula from above = NV = √(4 * k * T * R * B).
  5. Finally, calculate the Resistor Noise Voltage (NV) in nanovolts per square root hertz (nV/√Hz).
  6. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variables as an example problem to test your knowledge.

Resistance (R) = 1000 ohms

Temperature (T) = 300 Kelvin

Bandwidth (B) = 1000 Hz