Operational Amplifier Configurations to Know for Electrical Circuits and Systems I

Operational amplifiers are versatile components in electrical circuits, enabling various configurations for signal processing. From inverting and non-inverting amplifiers to integrators and comparators, these setups enhance functionality in applications like audio mixing, sensor processing, and impedance matching.

1. Inverting amplifier

   • Produces an output that is 180 degrees out of phase with the input.
   • The gain is determined by the ratio of two resistors (Rf and Rin).
   • Input impedance is equal to Rin, making it suitable for high-impedance sources.

2. Non-inverting amplifier

   • Provides an output that is in phase with the input signal.
   • Gain is calculated as 1 + (Rf/Rin), allowing for amplification without phase inversion.
   • High input impedance minimizes loading effects on the source.

3. Voltage follower (unity gain buffer)

   • Outputs the same voltage as the input, providing a gain of 1.
   • High input impedance and low output impedance, ideal for impedance matching.
   • Commonly used to isolate different circuit stages.

4. Summing amplifier

   • Combines multiple input signals into a single output.
   • The output voltage is a weighted sum of the input voltages, determined by resistor values.
   • Useful in audio mixing and signal processing applications.

5. Differential amplifier

   • Amplifies the difference between two input voltages while rejecting common-mode signals.
   • Configured with two input resistors and two feedback resistors for balanced operation.
   • Essential in applications requiring noise reduction, such as sensor signal processing.

6. Integrator

   • Produces an output voltage that is proportional to the integral of the input voltage over time.
   • Typically uses a capacitor in the feedback loop to achieve integration.
   • Commonly used in analog computing and signal processing applications.

7. Differentiator

   • Outputs a voltage that is proportional to the rate of change of the input voltage.
   • Utilizes a capacitor in series with the input to achieve differentiation.
   • Useful in applications requiring edge detection or signal shaping.

8. Comparator

   • Compares two input voltages and outputs a high or low signal based on which is greater.
   • Often used in threshold detection and signal conditioning applications.
   • Can be configured for hysteresis to prevent noise-induced switching.

9. Instrumentation amplifier

   • Provides high gain and high input impedance, ideal for low-level signal amplification.
   • Utilizes three op-amps for improved common-mode rejection and accuracy.
   • Commonly used in medical devices and sensor applications.

10. Voltage-to-current converter

    • Converts an input voltage signal into a proportional output current.
    • Utilizes feedback to maintain a constant current output regardless of load variations.
    • Useful in applications requiring current control, such as driving loads or sensors.