173k views
4 votes
Design an op amp circuit whose input is v

in

and output is given by v
out

=−5v
in

−3
dt
dv
in

1 Answer

2 votes

To design an op amp circuit with the given specifications, we can follow these steps: First, let's analyze the given equation for the output voltage, v_out. We have:

This equation tells us that the output voltage is proportional to the input voltage, v_in, and also depends on the rate of change of v_in with respect to time, dv_in/dt. To implement this equation using an op amp circuit, we can use an integrator circuit. An integrator circuit is capable of performing the integration operation, which is essentially finding the area under a curve.

The circuit diagram for an op amp integrator circuit is as follows:The non-inverting input terminal of the op amp is connected to the ground.The input voltage, v_in, is applied to the inverting input terminal of the op amp through a resistor, R. A capacitor, C, is connected between the inverting input terminal of the op amp and the output.Let's analyze how this circuit operates. When v_in changes, it causes a current to flow through the resistor, R. This current charges or discharges the capacitor, C, depending on the direction of change in v_in.

5. The voltage across the capacitor, Vc, is proportional to the integral of the current flowing through the resistor, R. Therefore, Vc is proportional to the integral of v_in with respect to time.

6. Since the output voltage of the op amp is equal to Vc, we can say that the output voltage is proportional to the integral of v_in. This satisfies the requirement of the given equation.

7. However, to achieve the specific scaling factors (-5 and -3) mentioned in the equation, we need to choose appropriate resistor and capacitor values.

8. By selecting R = 1 kΩ and C = 1 μF, we can achieve the desired scaling factors. This means that for every 1 V change in v_in, the output voltage will change by -5 V. Additionally, for every 1 V/second change in the rate of v_in, the output voltage will change by -3 V.

In conclusion, an op amp integrator circuit with R = 1 kΩ and C = 1 μF can be used to design a circuit with an input voltage, v_in, and an output voltage, v_out, given by v_out = -5v_in - 3 * (dv_in/dt). The circuit performs the integration operation and provides the desired scaling factors.

User Filipe V
by
8.1k points