Why is constant current source used in differential amplifier?

A constant-current source circuit can generate a current relatively stable against variations of power supply voltage, but not that stable against variations in the ambient temperature. A constant-current source circuit is typically used in an emitter-coupled-logic (ECL) circuit.

What is the main advantage of constant current bias over emitter bias in differential amplifier?

Answer: Constant current bias circuit supplies constant emitter current. It also provides very high source resistance since the AC equivalent of the DC current source is ideally an open circuit.

Why differential amplifier is used in op amp?

Differential amplifiers are used mainly to suppress noise. Noise consists of typical differential noise and common-mode noise, of which the latter can easily be suppressed with an op-amp. Current flowing into the ground of a circuit from another circuit causes a ground potential rise (noise).

Why constant current source is needed?

A constant current source is, thus, a very valuable component because it can supply steady current even if there are changes in resistance, even a wide variance in the resistance. This comes in use when a circuit needs a steady current supply, without fluctuations.

Why an ideal op-amp requires infinite bandwidth because?

An ideal op-amp requires infinite bandwidth because Explanation: An ideal op-amp has infinite bandwidth. Therefore, any frequency signal from 0 to ∞ Hz can be amplified without attenuation.

What is constant current bias?

amplifier in Unit 1 value of CMRR but if RE value is increased to very large value, IE(quiescent operating current) decreases. To maintain same value of IE, the emitter supply VEE must be increased. • To get very high value of resistance RE and constant IE, constant current bias is used.

Why the emitter follower is used in op amp?

The emitter follower is widely used as a buffer amplifier to reduce the loading on the previous stage and provide a lower impedance output for any following circuits. The electronic circuit design for the stage is also very straightforward and easy to accomplish.

How does a constant current source work?

A constant current source is a power generator whose internal resistance is very high compared with the load resistance it is giving power to. Because its internal resistance is so high, it can supply a constant current to a load whose resistance value varies, even over a wide range.

What is the difference between op-amp and differential amplifier?

The main difference between differential amplifier and operational amplifier is that a differential amplifier is an amplifier that amplifies a voltage difference between its inputs, whereas an operational amplifier is, in fact, a type of differential amplifier with a large open-loop gain, a high input impedance and a …