OPERATIONAL AMPLIFIERS AND LOGIC GATESA BRIEF DISCUSSION

OPERATIONAL AMPLIFIERS

Linear integrated circuits are being used in a number of applications such as fields like communication, medical electronics, instrumentation control

An important linear IC is operational amplifier

OP-AMP is a solid state device capable of sensing and amplifying dc and ac input signals.

OP-AMP is an amplifier with two inputs and a single output.

OP-AMP consists of 20 transistors, 11 resistors and one capacitor.

INVERTING AMPLIFIER

The input voltage is applied through the Vs to the inverting input through the input resistor RS

Here Is=If

The output voltage is out of phase with the input voltage

NON-INVERTING AMPLIFIER The input signal is

applied through vg

The resistor Rs is connected from the inverting input to ground.

The feedback resistor

Rf connected between the output and the inverting input.

Here the input and output voltages are in phase.

SUMMING AMPLIFIER An inverting amplifier,

used to sum two input voltages.

The output is –(V1+V2 )

The output voltage is equal to the sum of the input voltages and the circuit acts as a summing amplifier.

The negative sign indicates that OP-AMP is used in the inverting mode.

DIFFERENCE AMPLIFIER

The output voltage can be obtained by using superposition principle.

The output is V3-Vin

If all the external resistors are equal, the voltage difference amplifier functions as a voltage subtractor.

LOGIC GATES

Circuits which are used to process digital signals are called logic gates.

It has one or more inputs with only one output and the output appears only for certain combination of input signals.

The basic elements that make a digital system are “OR” ,”AND” and “NOT” gates.

OR GATE

AND GATE

NOT GATE

NAND GATE

NOR GATE

EXOR GATE

LOGIC GATES CAN BE SIMPLIFIED AS…..