What does a logarithmic amplifier do?

What logarithmic amplifiers do. Log amps are non-linear, analog amplifiers that produce an output that is the logarithm of the input signal or the signal’s envelope. They compress input signals having a large dynamic range into output signals with a fixed amplitude range.

How many op amps are present in the logarithmic amplifier?

Basically there are two log amp configurations: Opamp-diode log amplifier and Opamp-transistor log.

What are the disadvantage of basic log amplifier?

This type of log amp has three disadvantages: (1) both the slope and intercept are temperature dependent; (2) it will only handle unipolar signals; and (3) its bandwidth is both limited and dependent on signal amplitude.

What is an exponential amplifier?

Anti-Logarithmic Amplifier or Exponential Amplifier Anti-logarithmic or exponential amplifier (or simply antilog amplifier) is an op-amp circuit configuration, whose output is proportional to the exponential value or anti-log value of the input. Antilog amplifier does the exact opposite of a log amplifier.

Where do we use logarithmic amplifier?

Logarithmic amplifiers are used in many ways, such as:

• To perform mathematical operations like multiplication, division and exponentiation.
• To calculate the dB value of a given quantity.
• As a True RMS converter.

How does a logarithmic amplifier work?

A logarithmic amplifier, or a log amplifier, is an electronic circuit that produces an output that is proportional to the logarithm of the applied input. According to the virtual short concept, the voltage at the inverting input terminal of an op-amp will be equal to the voltage at its non-inverting input terminal.

What are the types of op-amp?

Op amps can be classified into 3 main types based on the input/output voltage range: Dual Supply, Single Supply, and Rail-to-Rail.

What is the use of logarithmic amplifier?

Logarithmic amplifiers are used in many ways, such as: To perform mathematical operations like multiplication, division and exponentiation. Multiplication is also sometimes called mixing.

What is meant by logarithmic amplifier?

A logarithmic amplifier, or a log amplifier, is an electronic circuit that produces an output that is proportional to the logarithm of the applied input.

How many types of op-amps are there?

There are two types of op-amps: single power supply type and dual power supply type. In the case of a single-supply op-amp, VCC is positive with respect to GND. In the case of a dual-supply op-amp, VCC is positive and VEE is negative with respect to GND.

What is the disadvantage of log antilog amplifier?

What is the disadvantage of log-antilog multiplier? Explanation: Log amplifier requires the input and reference voltage to be of the same polarity. This restricts log-antilog multiplier to one quadrant operation. Explanation: In an ideal frequency doubler, same frequency is applied to both inputs.

What is a log amplifier in opamp?

Opamp transistor log amplifier. In this configuration a transistor is placed in the feedback path of an opamp wired in inverting mode. Collector of the transistor is connected to the inverting input of the opamp, emitter to output and base is grounded. The necessary condition for a log amp to work is that the input voltage must be always positive.

What is a logarithmic amplifier?

A logarithmic amplifier, or a log amplifier, is an electronic circuit that produces an output that is proportional to the logarithm of the applied input. This section discusses about the op-amp based logarithmic amplifier in detail.

What is the output equation of a log amplifier?

Log amplifier is a linear circuit in which the output voltage will be a constant times the natural logarithm of the input. The basic output equation of a log amplifier is v V out = K ln ( V in / V ref ); where V ref is the constant of normalization and K is the scale factor.

What are the different types of log amps?

There are three basic architectures which may be used to produce log amps: the basic diode log amp, the successive detection log amp, and the true log amp which is based on cascaded semi-limiting amplifiers. The successive detection log amp and the true log amp are discussed in the RF/IF section.