Semiconductors/Op-Amps

Op-Amps Intro edit

Op-Amps stands for Operational Amplifier, a device usually manufactured as an Integrated Circuit (IC) . User don't need to know about the Itegrated Circuit inside in order to work with Op-Amps . All you need to know is that Op-Amps acts as an amplifier, it amplifies the difference of the 2 different voltages at input by a gain or amplification factor A

Output of an operational amplifier:

 

Ideally   is assumed to be equal to infinity. However, in practical op-amps, it has a high value. Furthermore, the gain   is a function of frequency.

Below is the most commonly used configuration of Op-Amps


Negative Amplifier edit

 
Inverting amplifier
 


  • The output voltage is a negative voltage equal to the input voltage amplified by a factor  

Positive Amplifier edit

 
Positive amplifer.
 
  • The output voltage is a positive voltage equal to the input voltage amplified by a factor  

Positive Buffer edit

   
  • From the circuit of Positive Amplifier, If R2 = 0 thì Vo = Vi

Negative Buffer edit

 
Inverting amplifier
  • From the circuit of Negative Amplifier, If Rf/Ri = 1 then Vo = - Vi

Further reading edit