An operational amplifier (op-amp) is a type of integrated circuit that is designed to perform high-gain linear amplification of electrical signals.
The basic building block of an op-amp is a differential amplifier stage, which amplifies the difference between two input voltages and provides a single-ended output. The inputs of an op-amp are typically referred to as the “non-inverting” (positive) input and the “inverting” (negative) input. The output of the op-amp is proportional to the voltage difference between the inputs.
Features of Op-amp
- High Gain
- Wide Bandwidth
- Differential Input
- High Input Impedance
- Low Output Impedance
- High CMRR
- Fast Response Time
Symbol of Op-amp
Types of Op-amp
There are several types of operational amplifiers (op-amps), which are commonly used for various applications.
- Voltage Feedback Op-Amp
- Current Feedback Op-Amp
- Instrumentation Amplifier (In-Amp)
- Comparator Op-Amp
- Unity Gain Op-Amp
Voltage Feedback Op-Amp
This is the most common type of op-amp and is used in a wide range of applications. It uses voltage feedback to regulate the gain and stability of the amplifier.
Current Feedback Op-Amp
This type of op-amp uses current feedback instead of voltage feedback to regulate the gain and stability of the amplifier. It is commonly used in high-frequency applications where a high level of stability is required.
Instrumentation Amplifier (In-Amp)
This type of op-amp is used in instrumentation and data acquisition systems, where high accuracy and low noise are required. It typically consists of two differential amplifiers, with the output of the first differential amplifier being fed as the input to the second differential amplifier.
Comparator Op-Amp
This type of op-amp is used in applications where the input signals need to be compared to a reference voltage. It operates in a comparator mode, where the output is either high or low, depending on whether the input voltage is higher or lower than the reference voltage.
Unity Gain Op-Amp
This type of op-amp is used as a buffer amplifier, where the gain is set to unity (1). It is used to isolate the input signal from the load, to prevent loading effects, and to drive high-impedance loads.
Working of Op-amp
The op-amp has two input terminals, the inverting (-) and non-inverting (+) inputs, and one output terminal. When a voltage is applied to the non-inverting input, the op-amp will output a voltage that is proportional to the difference between the voltage at the inverting input and the voltage at the non-inverting input, multiplied by the gain of the amplifier.
The gain of the op-amp is typically very high, often in the range of tens of thousands to millions. This high gain allows the op-amp to amplify very small input signals and produce large output signals. The gain can be controlled by using feedback resistors connected between the output and the inverting or non-inverting input.
Applications of Op-amp
- Amplifiers
- Filters
- Comparators
- Integrators and Differentiators
- Oscillators
- Audio Amplifiers
- Power Amplifiers