Download presentation

Presentation is loading. Please wait.

Published byHailie Redmon Modified over 5 years ago

1
1.6 Op-Amp Basics High input impedance Low output impedance Made using difference amplifiers having 2 inputs and at least 1 output 1 Note: Terminals for dc supply are omitted

2
1.6 Op-Amp Basics AC equivalent circuit 2 Ideal Practical Input impedance, R i is typically very high Output voltage, V o is amplifier gain times input signal taken through output impedance, R o which is typically low. Ideal op-amp would have infinite input impedance, zero output impedance and infinite voltage gain.

3
1.6 Op-Amp Basics Basic Op-amp – constant-gain multiplier 3 The input voltage V 1 is applied to the inverting terminal through R 1. The output voltage V o is fed back to the inverting terminal through R f. The output voltage V o is in antiphase with the input voltae V i The non-inverting terminal is grounded

4
Basic Op-amp – constant-gain multiplier AC equivalent circuit 1.6 Op-Amp Basics 4 Practical op-amp

5
Basic Op-amp – constant-gain multiplier If the practical op-amp is replaced by an ideal op-amp, the equivalent circuit becomes; 1.6 Op-Amp Basics 5

6
Basic Op-amp – constant-gain multiplier Redrawn equivalent circuit 6

7
1.6 Op-Amp Basics 7 Basic Op-amp – constant-gain multiplier By superposition theorem i) V 1 only (set –A v V i = 0) ii) –A v V i only (set V 1 = 0)

8
Basic Op-amp – constant-gain multiplier 1.6 Op-Amp Basics 8 Solving for V i, gives us;

9
Basic Op-amp – constant-gain multiplier 1.6 Op-Amp Basics 9 Usually and Then; The ratio V o /V 1 is dependent on the external components R f and R 1 only.

10
Basic Op-amp – unity gain 1.6 Op-Amp Basics 10 If R f = R 1 ; Shown that the output voltage equal to input voltage with 180° phase inversion.

11
Basic Op-amp – constant magnitude gain 1.6 Op-Amp Basics 11 If R f = 10R 1 ; Shown that the output voltage is equal to 10X the input voltage with 180° phase inversion.

Similar presentations

© 2020 SlidePlayer.com Inc.

All rights reserved.

To make this website work, we log user data and share it with processors. To use this website, you must agree to our Privacy Policy, including cookie policy.

Ads by Google