In designing level meter signals, temperature control hysteresis, oscillators, signal generators, audio amplifiers, mic boosters, active filters such as bass tape filters, mixers, signal converters, integrators, differentiators, comparators and a host of other applications, -back component data called op-amp.
Components of analog electronics in the packaging of ICs (integrated circuits) is indeed a versatile component and used in many applications until now. Just by adding some resistors and potentiometers, in an instant (or two strokes) a class B audio pre-amp can be assembled on top of a proto-board.
Differential Differential
Op-amps are also called differential amplifiers. In accordance with this term, the op-amp is an IC component that has two input voltages and 1 output voltage, where the output voltage is proportional to the voltage difference between the two inputs. The differential amplifier shown in the figure below is the basic circuit of an op-amp.
Differential Strengthening Images
In such sequence, the equation at Vout is Vout = A (v1-v2) where A is the gain value of this differential amplifier. The inputv1 point is said to be a non-iverting input, since the voltage is a phase with v1. Whereas the opposite point v2 is said to be inverting input because of the opposite phase with the transient vout.
Op-amp diagram
The op-amp consists of several parts, the first is the differential amplifier, then there is the gain stage, then there is the level shifter circuit and then the final amplifier which is usually made with a push-pull class B amplifier. The following shows the diagram of the op-amp consisting of several parts.
Schematic Diagram Op-Amp Symbol
The op-amp symbol is like in the schematic image of Op-Amp symbol with 2 inputs, non-inverting (+) and inverting input (-). Generally the op-amp works with dual supply (+ Vcc and -Vee) but many op- Amp is made with a single supply (Vcc – ground). The circuit symbol inside the op-amp of Fig. 2 (b) is the general parameter of an op-amp. Rin is an input resitution whose ideal value is infinite (infinity).
Rout is the output resistance and the ideal resistance is 0 (zero). While AOL is an open loop gain value and its ideal value is infinite. Currently there are many types of op-amps with specific characteristic. Op-amp standard type 741 in 8-pin DIP IC packaging has been made since the 1960’s. For the same type, each manufacturer issues a series of ICs with different insial or names. For example known MC1741 from motorola, LM741 made by National Semiconductor, SN741 from Texas Instrument and so forth.
Depending on its manufacturing technology and IC design, the characteristics of an op-amp may differ from other op-amps. Table-1 shows some important op-amp parameters and their ideal values as well as a real example of the LM714 parameter.
Op-Amp Parameter Table