Explain the block diagram of operational amplifier?

Answer 1

:- Operational amplifier is a multistaged amplifier. Generally four stages are used operational amplifier.

1. Input stage :- At input stage dual input balanced output amplifier is used. It is used to provide high input impedance and voltage gain.
2. Intermediate stage :- At intermediate stage dual input unbalanced output amplifier is used. It is used to provide more and more high voltage gain of the amplifier.
3. Buffer level shifting stage :- At level shifting input stage Emitter follower circuit is used. It is used to provide D.C level shifting to the output stage or high input impedance to the input stage
4. Output stage :- At output stage complementary push - pull amplifier is used. It is used to provide low output impedance to the amplifier.

Answer 2

It's function is to perform integer and difference solutions to analog inputs. It has - and + inputs. By choosing capacitive or resistive feedback you can alter the signal as needed.

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An operational amplifier, often called an op-amp , is a DC-coupled high-gain electronic voltage amplifier with differential inputs and, usually, a single output.

Typically the output of the op-amp is controlled either by negative feedback, which largely determines the magnitude of its output voltage gain, or by positive feedback, which facilitates regenerative gain and oscillation. High input impedance at the input terminals and low output impedance are important typical characteristics.

Op-amps are among the most widely used electronic devices today, being used in a vast array of consumer, industrial, and scientific devices.

External components govern the circuit characteristics.

As well as an amplifier designed to respond to a difference in voltage at the two input terminals, another type is designed to respond to different currents at the inputs. This is the Norton op-amp.

Modern designs are electronically more rugged than earlier implementations and some can sustain direct short-circuits on their outputs without damage.

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An operational amplifier is a voltage amplifier that amplifies the differential voltage between a pair of input nodes. It is a DC-coupled high-gain electronic amplifier with differential inputs and usually a single output. One input is an inverting input and the other input is a non-inverting input.

Within limits, the output goes to whatever value is required in order to make the two inputs have the same value. This means there is usually a negative feedback circuit between output and the inverting input. For an ideal operational amplifier, also called an op amp, the amplification gain is infinite.

Answer 3

An operational-amplifier works by comparing its two inputs and generating an output that makes the two inputs the same. There is generally some kind of feedback between output and input so, in effect, the operational-amplifier is controlling the device connected to the output by comparing the output state with the input or reference state.

Answer 4

the op amp block diagram has 4 stages:

1.input stage(dual i/p balanced o/p)

2.intermediate stage(dual i/p unbalanced o/p)

3.level shifter /translator

4.output stage

1.input stage:

• it is a dual i/p and balanced output differential amplifier
• it has 2i/p terminals and 2 o/p terminals
• it establishes very high input impedence
• it provides most of the gain of the circuit

• it amplifies the difference in the voltages applied and rejects any common signal

2.intermediate stage:

• it is a dual i/p and unbalanced o/p diff. amp.
• 2i/ps and 1 o/p
• it provides additional gain to the circuit

3.level shifter/translator:

• due to the direct coupling of the previous two stages,we can observe a dc shift in the output of the second stage
• this dc shift is undesirable because,the output voltage swing is limited and causes error in dc o/p signal
• so level shifter is used to shift the dc level of the o/p of the second stage to zero volts w.r.t ground
• level shifter is usually a emitter follower with potential divider or constant current bias circuit

4.output stage:

• it provides zero o/p impedance so that it can drive almost any number of devices
• it is usually a symmetric push pull complementary circuit
• it increases the o/p voltage swing and increases the current supplying capabilities of the circuit