Final answer:
To design the summing amplifier, one must select resistor values that satisfy the current limit of 120μA and achieve the intended voltage summation, considering the relationship V = V1 + V2 + V3 where V1, V2, and V3 correspond to the voltage drops across their respective resistors.
Step-by-step explanation:
Designing an Ideal Three-Input Inverting Summing Amplifier
To design an ideal three-input inverting summing amplifier that conforms to the input voltages v1 = 2 + 2sinωt V, v2 = 0.5sinωt V, v3 = -4 V, and aims for a desired output voltage vO = -6sinωt V, we apply the concept that the sum of the voltage drops across the individual resistors equals the output voltage of the source. More formally, the relationship is represented as V = V1 + V2 + V3, where the voltage drops V1, V2, and V3 correspond to their respective current/resistor products IR1, IR2, IR3.
Given that the maximum current in any resistor is to be limited to 120μA, the resistor values should be selected appropriately to satisfy the current limit and achieve the precise summation of input voltages resulting in the desired output voltage. This involves calculating the needed resistance values based on the peak current, which is limited by the maximum current specification. The current through the resistors in a summing amplifier configuration will be in phase with the voltage, as stated by the relationship i = Io sin ωt, where i is the instantaneous current and Io is the peak current.