*Operational amplifiers* are linear devices that are used extensively in signal conditioning, filtering or to perform mathematical operations such as add, subtract, integration and differentiation.

The name Op Amp comes from “operational amplifier.”, Op Amp is a voltage amplifying device designed to be used with external feedback components such as resistors and capacitors between its output and input terminals.

**Op -Amp Characteristics**

- The op amp has infinite open-loop gain
- The input impedance of the +/− inputs is infinite. (The inputs are ideal voltmeters
- The output impedance is zero. (The output is an ideal voltage

source.) - No current flows into the +/− inputs of the op amp. This is really a restatement of golden rule 2.
- In a circuit with negative feedback, the output of the op amp will try to adjust its output so that the voltage difference between the + and − inputs is zero (V+ = V−).

###### IDEAL OP AMP BEHAVOIR.

###### Basic Op Amp Building Blocks

**Inverting Amplifier**

**Non-inverting Amplifier**

**Voltage Follower**

**Current-to-Voltage Converter**

**Summing Amplifier**

**Differential Amplifier**

**Integrator**

**Differentiator**