Basic Op Amp circuits: Difference between revisions

From Class Wiki
Jump to navigation Jump to search
Fonggr (talk | contribs)
Fonggr (talk | contribs)
Line 1: Line 1:
=Basic Op Amp Circuits=
=Buffer Amplifier=
[[Image:BufferAmplifier.PNG|thumb|300px|Buffer Amplifier ]]
[[Image:BufferAmplifier.PNG|thumb|300px|Buffer Amplifier ]]
*Used to transfer voltage but not current to the following circuit. This amplifier can be used to negate the loading effects. No current flows through the amplifier, thus there is no voltage drop through the input resistor (going to the buffer amplifier).
=Inverting Amplifier=
[[Image:InvertingAmplifier.png|thumb|300px|Inverting Amplifier]]
[[Image:InvertingAmplifier.png|thumb|300px|Inverting Amplifier]]
*Uses negative feedback to invert and amplify voltage. Using nodal analysis at the negative terminal, the gain is found to be <math>-\frac{R_2}{R_1}</math>
=Summing Amplifier=
[[Image:Summing_Amplifier.PNG‎|thumb|300px|Summing Amplifier]]
[[Image:Summing_Amplifier.PNG‎|thumb|300px|Summing Amplifier]]
*<math>V_o=-R_f \left( \frac{V_3}{R_3}+\frac{V_2}{R_2}+\frac{V_1}{R_1}\right)</math>
*If all resistances are equal, then the output voltage is the (negative) sum of the input voltages
=Noninverting Amplifier=
[[Image:Noninverting_Amplifier.PNG‎|thumb|300px| Noninverting Amplifier]]
[[Image:Noninverting_Amplifier.PNG‎|thumb|300px| Noninverting Amplifier]]
*Buffer amplifier is used to transfer voltage but not current to the following circuit. This amplifier can be used to negate the loading effects. No current flows through the amplifier, thus there is no voltage drop through the input resistor (going to the buffer amplifier).
*<math>V_o=V_{in} \left(1+\frac{R_2}{R_1}\right)</math>
*Inverting amplifier uses negative feedback to invert and amplify voltage. Using nodal analysis at the negative terminal, the gain is found to be <math>-\frac{R_2}{R_1}</math>
*Summing amplifier <math>V_o=-R_f \left( \frac{V_3}{R_3}+\frac{V_2}{R_2}+\frac{V_1}{R_1}\right)</math>
**If all resistances are equal, then the output voltage is the (negative) sum of the input voltages
*Noninverting amplifier <math>V_o=V_{in} \left(1+\frac{R_2}{R_1}\right)</math>

Revision as of 13:43, 11 January 2010

Buffer Amplifier

Error creating thumbnail: File missing
Buffer Amplifier
  • Used to transfer voltage but not current to the following circuit. This amplifier can be used to negate the loading effects. No current flows through the amplifier, thus there is no voltage drop through the input resistor (going to the buffer amplifier).

Inverting Amplifier

Error creating thumbnail: File missing
Inverting Amplifier
  • Uses negative feedback to invert and amplify voltage. Using nodal analysis at the negative terminal, the gain is found to be R2R1

Summing Amplifier

Error creating thumbnail: File missing
Summing Amplifier
  • Vo=Rf(V3R3+V2R2+V1R1)
  • If all resistances are equal, then the output voltage is the (negative) sum of the input voltages

Noninverting Amplifier

Error creating thumbnail: File missing
Noninverting Amplifier
  • Vo=Vin(1+R2R1)