Differential amplifier as one of the main elements in electronics circuits

In the design of electronic circuits, radical changes often occur, under which the very principles of creating different devices change. Such revolutionary changes can occur as a result of the emergence of new devices and the development of technology. A good example in this case is the transition from electron tubes to semiconductor devices. Or in the development of circuit solutions, on the basis of which it becomes possible to create efficiently operating new devices. Differential amplifier appeared relatively recently, but immediately became in demand in many industries. Schemes using such amplifiers are widely used in industrial electronics. On their basis, many household appliances, tape recorders, amplifiers, etc. have been designed.

The principle of operation of such an amplifier is simple enough, and it is in this lies the popularity of this device. It consists of two inputs / outputs and has a high gain.

The differential amplifier responds to the difference in the input potentials by the appearance of a voltage at the output. The output level will be equal to the potential difference at the input multiplied by the amplification factor of the amplifier itself. In other words, such a scheme will try to restore the initial equilibrium of the potentials at the input, by increasing the voltage level at the output. This property is widely used in the construction of various schemes. The differential amplifier became a harbinger of the appearance of operational amplifiers (OA), which became widely used in various electronic circuits.

Operational amplifiers have gained great popularity and have performed well. A small, compact, high-speed device has become firmly embedded in electronic circuits used to control various technological processes. You can also see OS in household appliances. A large number of schemes have been created with their application.

For example, the factor of such an amplifier can easily be made manageable if feedback is created. For this, we connect the output / input of the circuit through the limiting resistance. The input signal is also passed through the limiting resistor. As you can see, the operational amplifier is easy to make manageable, the coefficient of the circuit is calculated by the ratio of the feedback resistance to the nominal value of the input resistor.

If this coefficient is made equal to unity and feedback is organized through the inverse input, then it is possible to create a differential amplifier. For this purpose, the voltage to the non-inverted input is fed through a voltage divider with equal resistor values in each arm. By collecting such a scheme, we obtain a differential amplifier by ay. Changing the ratio of resistors can affect the parameters of the entire circuit. The main, of course, is the gain.

Using differential amplifiers in electronics, you can achieve the implementation of almost any project. They perfectly behave in logic, protection or control schemes.

The drawbacks of the circuits on the op amp include a small drift of the output signal, depending on the operating temperature of the device. This problem is solved by using various circuit solutions.