Summing Op Amp. Summing amplifier is basically an op amp circuit that can combine numbers of input signal to a single output that is the weighted sum of the applied inputs. A summing amplifier is an inverted op amp that can accept two or more inputs.
Let s say i want to use my summing op amp in an application where what i want is i want v out to equal say minus two times va plus three times vb. Summing amplifier or op amp adder using inverting op amp. Despite the high input impedance and in phase output signal that the non inverting summing amplifier can provide the inverting summing amplifier is more common as it s output is a simple weighted sum.
Fig 1 shows a three input summing amplifier.
The inverting input of the op amp is. So this says vb. So it s just va. Then the output voltage of the summing amplifier circuit above is given as 45 mv and is negative as its an inverting amplifier.
