Who invented operational amplifier

They can be designed to act as a voltage amplifying device when used with active components such as transistors and passive components like resistors and capacitors to provide the desired response.

When signals pass through discrete elements in an analog circuit, they tend to decrease in amplitude—their voltage level decreases, but an op amp can help buffer and boost the amplitude of such signals, hence, delivering a signal that is useful at the output. Op amps are very adaptable and versatile to many electronic circuits. They are used in audio and video applications, voltage regulators, precision circuits, analog-to-digital and digital-to-analog converters, and many other applications.

Designers should consider gain, input impedance, output impedance, noise, and bandwidth as well as the following factors to consider when selecting an op amp IC:.

An op amp can come in a number of channels anywhere between 1 and 8 with the most common op amps having 1, 2, or 4 channels.

The gain of an op amp represents how much greater in magnitude its output will be than its input, hence its amplification factor. This is usually defined as an open-loop gain or large signal voltage gain. Infinite open-loop gain implies that a zero voltage at the input would turn the output fully on or off and although it seems impractical, it basically means that you can quickly switch your output from on to off just with a small change in input voltage.

Typical real values are in the range of about 20, to , The large signal voltage gain , usually denoted as AVD, is the ratio of the change in the output to the differential voltage change in the input, measured at DC—at low frequency—with the amplifier producing a large voltage output.

The difference is that it is measured with an output load and therefore takes into account loading effects. This is the ratio of the input voltage to the input current. Ideally, this value is infinite but most op amps that are now in production have typical values in the order of millions of ohms.

The input impedance of the op amp is desirably high enough to get all the voltage from an input to the target without loss. Typical input leakage current is from a few pico-milliamps. This is the small-signal impedance between the output terminal and ground.

It is usually in series with the load thereby increasing the output available for the load. The output impedance is assumed to be zero for an ideal amplifier, hence it should be small for real values. Op amps have internally associated parasitic noise sources. They are usually measured at the output and referenced back to the input. The most significant of them is the Equivalent Input Noise Voltage, often specified by e n. It is given as voltage, V n , per root hertz at a specific frequency.

It is desirable for this value to be as small as possible. The bandwidth of an op amp is the allowable range of frequency of the input signal which it can reproduce. An ideal op amp allows all frequency hence, its bandwidth is infinite and can amplify any frequency signal from DC to the highest AC frequencies. This is not the case for practical op amps, which are limited to a certain range and do not perform well above a certain frequency.

The parameter Gain Bandwidth Product GBP is often used to describe the limit of the bandwidth of an op amp with respect to its gain. It is equal to the frequency where the gain of the amplifier becomes unity.

The slew rate of an op amp is the rate of change in the output voltage caused by a step-change in the input. Ideally, the slew rate of an op amp should be infinite thus allowing the output to be exactly an amplified copy of the input, without any distortion. In real-world applications, the higher the value of slew rate, the faster the output can change and the more easily it can reproduce high-frequency signals. This is the maximum differential voltage needed at the input to get a 0V output.

Ideally, it is zero when both inputs to the op amp are zero. Hence, it should be small enough. Its input and output come with overload protection. This op amp also features no latch-up when the common-mode range is exceeded. It is a direct, plug-in replacement for other op amps like the C, LM, MC, and in most applications. This op amp is very popular due to its flexibility, availability and cost-effectiveness. It is suitable for transducer amplifiers, DC gain blocks and conventional op amp applications.

The RC , electrically similar to the uA, is a dual general-purpose operational amplifier. It is device is specified for operation and it has a typical gain-bandwidth product of 3 MHz. Its features make it suited for voltage-follower applications. It operates from a single power supply with a range of It has a wide gain-bandwidth of 3 MHz. Suitable for high-fidelity and audio pre-amplifier applications. This amplifier is ideal to provide superior sound quality and speed for exceptional audio performance.

It has a typical input bias current of 25nA. Suitable for industrial, oscillators, logic voltage translation applications and more. It typically has a gain-bandwidth of 0. The OP07 is a direct replacement for , A, and OP05 amplifiers and it is suitable for high gain instrumentation applications.

An op-amp, technically, is a high-gain voltage amplifier with differential inputs. Using appropriate negative feedback, a single op-amp can add or subtract two voltage signals, multiply by a constant, or integrate voltage over time. Stringing together many op-amps lets one compute complicated formulas. Many analog computers relied on vacuum-tube op-amps, available commercially from George A.

In , Bob Widlar at Fairchild Semiconductor made an op-amp on a single integrated circuit. He later became the analog wizard-in-residence at National Semiconductor, widely known not only for his creative and reliable designs, but also for his colorful personality. Experience with fire control systems during World Word II led Philbrick to manufacture analog computing components. Widlar was among the most brilliant and eccentric designers of analog integrated circuits.

His ingenious designs at Fairchild and National Semiconductor are legendary—as are his stunts.