INSTRUMENTATION AMPLIFIER

Circuit diagram:

 

gs

 

Theoretical explanation:

Differential amplifier with high input resistance is used in instrumentation amplifier. Its gain can be precisely set by an internal signal or external resistor. The high common mode rejection ratio makes this amplifier very useful in recovering a small signal buried in large common mode offers and noise.

The instrumentation amplifier is a closed loop device with carefully set gain. The instrumentation amplifier consists of two stages. The input first stage offers very high impedance to both input signals and allows setting gain with a single resistor. The second stage is a differential amplifier with output, negative feedback and ground connections are all brought out.

The input stage consists of two matched op amp. Each stage consists of two matched op amp. Each input V1 and V2 is applied to non inverting input terminal of its op amp. This op amp provides very high input resistance. The output of op amp is connected through a string of resistors.

The two resistors are R and Rg. Output voltage, Vo = (V2-V1) (1+2R/Rg)

Therefore decrease in value of Rg will increase the output voltage Vo. To increase in value of gain the value of Rg has to be decreased.

Advantages:

Even a small value of input voltage can be amplified using instrumentation amplifier.

Disadvantages:

For transmission purpose for long range, noise also gets superimposed along the original wave. Therefore specific cables are used to reduce noise.

 

 

Like it on Facebook, +1 on Google, Tweet it or share this article on other bookmarking websites.


Written by
shyam
  • No comments found

Latest Articles

In this article, you shall learn how to withdraw your money from your PayPal account. To withdraw your money, the first thing you need to do is ‘Login’
Humans are social being and we need to interact with people. A friend plays an important role in one's life. Sometimes, we face loneliness and feel like
Donald Trump won the election but lost the popular vote. This is the dichotomy of the American election where it is not the case of first past the post.

Related Articles

The Beatles are undoubtedly the most popular rock band of all times... They took rock music to heights that could never be scaled by their contemporaries.
  Rock music has diversified a lot in the last few decades, & there are far too many genres under rock music currently. So now there are ardent
Well I don't think there's a better way to express your love for someone, than through songs. Cards, or the well planned 'unexpected gift at an unexpected
If you're a Rock fan, you'll be aware that Rock music helps to raise your energy levels quickly. It creates a buzz, that re-energizes you. In this post
Rock music...Some call it 'cacophonic drivel', some say it started off wanton behavior among the youth....But for me it's a source of wisdom, a source