An inverting summing amplifier can be configured to

An inverting summing amplifier can be configured to

• A. Average several input voltages, apply specific weights to each input as a nulling voltage.
• B. Provide a non-inverting gain of two.
• C. Filter high-frequency components.
• D. Convert DC to AC.

Answer: (A)

The main idea is that an inverting summing amplifier combines multiple input voltages by summing their currents at the inverting node and converting that total into a single output voltage through the feedback resistor. The output is a weighted sum of the inputs, with the weights set by the ratios of each input resistor to the feedback resistor: Vout = -Rf (V1/R1 + V2/R2 + ... + VN/RN) This means you can average several inputs by choosing equal input resistors and selecting the feedback resistor so that Rf/R equals 1/N. Then Vout becomes -(1/N) times the sum of the inputs, i.e., the average (up to a sign). You can also weight inputs differently simply by picking different input resistors: if you want one input to contribute more, give it a smaller R value relative to the others. The option mentioning a non-inverting gain of two isn’t achieved with this basic summing setup, since that would require a different topology. Filtering high-frequency components or DC-to-AC conversion aren’t the primary functions of a plain inverting summing amplifier unless additional reactive elements or stages are added.

The main idea is that an inverting summing amplifier combines multiple input voltages by summing their currents at the inverting node and converting that total into a single output voltage through the feedback resistor. The output is a weighted sum of the inputs, with the weights set by the ratios of each input resistor to the feedback resistor:

Vout = -Rf (V1/R1 + V2/R2 + ... + VN/RN)

This means you can average several inputs by choosing equal input resistors and selecting the feedback resistor so that Rf/R equals 1/N. Then Vout becomes -(1/N) times the sum of the inputs, i.e., the average (up to a sign). You can also weight inputs differently simply by picking different input resistors: if you want one input to contribute more, give it a smaller R value relative to the others.

The option mentioning a non-inverting gain of two isn’t achieved with this basic summing setup, since that would require a different topology. Filtering high-frequency components or DC-to-AC conversion aren’t the primary functions of a plain inverting summing amplifier unless additional reactive elements or stages are added.