Summing point concept of Op-amp with negative feedback
Q. According to figure, 'A' is referred as the summing point because of ______.
- Published on 26 Oct 15a. Addition of input and feedback currents at point 'A'
b. Addition of only input currents at point 'A'
c. Both a & b
d. None of the above
ANSWER: Addition of input and feedback currents at point 'A'
Summing point is basically a point where all input as well as output or (may be feedback) are summed together. This point simply performs summation of all incoming currents coming towards it. In figure, point 'A' is a summing point. Since the configuration of Op-amp is exhibited to be of negative feedback in above drawn figure, so some part of output is connected at the input through point 'A' is also taken into consideration for the purpose of algebraic sum evaluation.
Generally, the concept of summing point and virtual ground are explained simultaneously for the semantic configuration requirement.
