Electronics - Basic Op-Amp Circuits - Discussion

I want an explanation for scaling adder?

Scaling adder means summing amplifier.

The scaling adder is a variation of the averaging amplifier. Wherein the feedback resistor of the scaling adder is equal to or greater than the value of its input resistors. The scaling adder multiplies each input voltage by a factor of the ratio of the feedback resistor and input resistor. It then adds all of the input voltages producing a scaled sum of the inputs. That is scaling adder.

The scaling adder is a variation of the averaging amplifier. Wherein the feedback resistor of the scaling adder is equal to or greater than the value of its input resistors. The scaling adder multiplies each input voltage by a factor of the ratio of the feedback resistor and input resistor. It then adds all of the input voltages producing a scaled sum of the inputs. That is scaling adder.

DAC has the same circuit as that of the scaling adder where each input is multiplied by the ratio of the feedback resistance to input resistance which determines its value, for example, bit 0 has Rin = 8R, bit 1 has Rin = 4R and Rf = feedback resistance = R.

Then, Vo = Rf(Vin1/Rin1 +Vin2/Rin2),
Vo = R(Vin1/8R+Vin2/4R) = (Vin1)/8 + (Vin2)/4 representing a digital signal 10 as an analog signal.

DAC has the same circuit as that of the scaling adder where each input is multiplied by the ratio of the feedback resistance to input resistance which determines its value, for example, bit 0 has Rin = 8R, bit 1 has Rin = 4R and Rf = feedback resistance = R.

Then, Vo = Rf(Vin1/Rin1 +Vin2/Rin2),
Vo = R(Vin1/8R+Vin2/4R) = (Vin1)/8 + (Vin2)/4 representing a digital signal 10 as an analog signal.