Enter the scale factor, the input voltage (volts), and the normalization constant (volts) into the calculator to determine the Log Amplifier Voltage. 

Log Amplifier Voltage Formula

The following formula is used to calculate the Log Amplifier Voltage.

Vo = K * ln ( Vi / Vref)
  • Where Vo is the Log Amplifier Voltage (volts)
  • K is the scale factor 
  • Vi is the input voltage (volts) 
  • Vref is the normalization constant (volts) 

To calculate the log amplifier voltage, multiply the scale factor by the natural log of the ratio of input voltage to the normalization constant.

How to Calculate Log Amplifier Voltage?

The following example problems outline how to calculate Log Amplifier Voltage.

Example Problem #1

  1. First, determine the scale factor. In this example, the scale factor is determined to be 76 .
  2. Next, determine the input voltage (volts). For this problem, the input voltage (volts) is measured to be 5 .
  3. Next, determine the normalization constant (volts). In this case, the normalization constant (volts) is found to be 4.
  4. Finally, calculate the Log Amplifier Voltage using the formula above: 

Vo = K * ln ( Vi / Vref)

Inserting the values from above and solving yields: 

Vo = 76 * ln ( 5 / 4) = 16.958 (volts)

Example Problem #2

Using the same method as above, determine the variables required by the formula. For this example problem, these are:

scale factor = 80

input voltage (volts) = 15

normalization constant (volts) = 9

Enter these given values into the calculator or above yields: 

Vo = 80* ln ( 15 / 9) = 40.866 (volts)