The book provides a comprehensive exploration of operational amplifiers (op-amps) and their myriad applications in both linear and non-linear circuits. Beginning with a foundational introduction to op-amps, the text delves into linear circuits, followed by an examination of non-linear circuits. The middle sections cover essential topics such as waveform generators, active filters, and data converters. Subsequent chapters expand on the use of op-amps in more complex analog and digital applications, including voltage regulators, analog multipliers, dividers, and the versatile 555 timer circuits. The final chapters focus on the implementation of logic gates, combinational circuits, and flip-flops using op-amps. The appendices offer practical insights through various tutor kits developed by the author and additional resources, making this book an invaluable resource for both students and professionals in the field of electronics. Operational amplifier, also called an op-amp, is an integrated circuit, which can be used to perform various linear, non-linear and mathematical operations. An op-amp is a direct coupled high gain amplifier. You can operate op-amp both with AC and DC signals. Operational amplifiers, or op-amps as they are more commonly called, are one of the basic building blocks of analogue electronic circuits.