Log Amplifier Voltage Calculator, Formula, Log Amplifier Calculation

Log Amplifier Voltage Calculator

Enter the values of gain of the amplifier, K, input voltage, V_i(V) and reference voltage, V_ref(V) to determine the value of Output voltage, V_o(V).

Log Amplifier Voltage Formula:

Log amplifier voltage is a key concept in electronics, especially in signal processing and measurement applications.

A log amplifier produces an output voltage proportional to the logarithm of its input voltage.

This is particularly useful in applications requiring a wide dynamic range of signal processing, such as audio signal processing, RF signal processing, and instrumentation.

Output voltage, V_o(V) in volts is calculated by the product of gain of the amplifier, K and ln of ratio of input voltage, V_i(V) in volts and reference voltage, V_ref(V) in volts.

Output voltage, V_o(V) = K * ln (V_i(V) / V_ref(V))

V_o(V) = output voltage in volts, V.

K = gain of the amplifier.

V_i(V) = input voltage in volts, V.

V_ref(V) = reference voltage in volts, V.

Log Amplifier Voltage Calculation:

1. Calculate the output voltage of a log amplifier with an input voltage of 2 volts, a reference voltage of 1 volt, and a constant K of 2.

Given: K = 2, V_i(V) = 2V, V_ref(V) = 1V.

Output voltage, V_o(V) = K * ln (V_i(V) / V_ref(V))

V_o(V) = 2 * ln(2 / 1)

V_o(V) = 2 * ln(2)

V_o(V) = 2 * 0.693

V_o(V) = 1.386V.

2. Suppose a log amplifier has an input voltage of 5 volts, a reference voltage of 2 volts, and the output voltage is 2.748V. Calculate the gain of the amplifier.

Given: V_o(V) = 2.748V, V_i(V) = 5V, V_ref(V) = 2V.

Output voltage, V_o(V) = K * ln (V_i(V) / V_ref(V))

K = V_o(V) / ln (V_i(V) / V_ref(V))

K = 2.748 / ln(5/2)

K = 2.748 / ln(2.5)

K = 2.748 / 0.916

K = 3.

Applications and Considerations:

• Signal Processing: Log amplifiers are extensively used in signal processing applications to compress the dynamic range of signals.
• Instrumentation: In measurement systems, log amplifiers help in handling signals with a wide range of magnitudes.
• Audio and RF Applications: They are useful in audio signal processing and RF applications where signals can vary over several orders of magnitude.

Log amplifier using op-amp | Logarithmic Amplifier