Operational Amplifier (Op-Amp) - Lab Report Example

Download file to see previous pages ed, high gain, voltage amplifier. They form the basis of a wide array of electronic circuits, including amplifiers, buffers, comparators, and analogue-digital/digital-analogue converters. An op-amp is represented in schematic notation by the following symbol: Figure 1 - Circuit Diagram Element Where V+ and V- are the differential inputs, VS+ and VS-, are the positive and negative supply voltages, and Vout is the output of the amplifier. While they are represented as a single element, op-amps are in fact composed of many circuit elements, and are conventionally sold as monolithically integrated silicon chips. 1.1 Origins and Development of the Operational Amplifier The operational amplifier can trace its origins back to fledgling telecommunications industry in the United States at the turn of the 19th century. With the invention of the telephone, there was demand to carry electronic voice communications over longer and longer distances. The challenge was to build signal repeating equipment that minimized problems like distortion and crosstalk, so that multi-channel communications could be carried from one side of the country to the other. Advances in electronic equipment and amplifier design eventually led to the development of the first operational amplifiers at Bell Labs in the 1940s. Vacuum tube devices were essential to the development of amplifier technology, because they made possible for the first time the non-linear manipulation of voltage and current. “The Fleming Diode”, patented in 1904 by J.A. Fleming [1], was the first major breakthrough in this respect because it allowed for the rectification of current. Then in 1906, Lee De Forest [2] built upon this work with “The Audion”, a three-element triode vacuum tube that was the first device capable of signal amplification. Amplifiers built in the following years suffered from stability problems, as they used a positive feedback principle, and distortion due to the generation of harmonics by vacuum tubes. Harold Black [3], in 1927 while searching for a means of improving linearity and stability of currently-used positive feedback amplifiers, came up with the negative feedback amplifier principle. The idea of deliberately sacrificing gain in to improve stability ran counter to conventional ideas at the time, and it took 9 years for the original patent application to be accepted. Once implemented, however, the advantages of this approach quickly became clear. Within a few years the theory for stable amplifier design was formalized by Nyquist and Bode, two names now synonymous with fundamental electrical engineering principles, during their work at Bell Labs. At this ...Download file to see next pagesRead More