Op-amp integrator circuit has been explained with derivation and 4 Examples have been solved for better understanding,

Op-Amp Integrator:
An integrator circuit basically an inverting amplifier, Where we replace feedback resistor with reactive element or frequency dependent element such as capacitor, An integrator op amp produces an output voltage that is both proportional to the amplitude and duration of the input signal.

Op-Amp integrator behavior on fixed input voltage:
For a fixed input voltage, Initially, the output voltage will increase in opposite direction because of inverting action, and at a certain point, the output will get saturated.

Op-Amp integrator behavior on square wave input:
If we apply a square wave pulse as an input to the integrator circuit, The output will be a triangular wave, in such a case the circuit is called a Ramp generator.

Integrator behavior on sine wave input:
If the input of an integrator is sine wave the output will be a cosine wave, Which is 90 degrees out of phase with the input signal.

Integrator behavior on triangular wave input:
In a triangular wave input the integrator produces a sinusoidal output.

Limitations of simple integrator circuit:
In simple integrator circuit, At very low frequencies or at DC level, due to the reactance of the capacitor is very high and acts as an open circuit, So the gain of the op amp will be very high and acts as an open loop inverting amplifier, This will result the saturation of the output voltage, So we can say that op-amp acts as an low pass filter,
If we are using at integrator op-amp at low frequencies then also it is quite possible that output will get saturated or distorted, the problem is cause by Input offset voltage and Input bias current.

Practical integrator circuit:
The solution for the limitations of a simple integrator circuit is quite simple, by adding a feedback resistor in parallel with the feedback capacitor, we provide a consistent path for the steady DC currents,
Now at low frequencies, the feedback capacitor acts as an open circuit, So the gain of the op-amp is inverting gain -Rf/Rin.
A compensation resistor being connected at the Non-inverting terminal to avoid input bias current.

Conditions for proper integration of input signal:
For proper integration of input signal, the input signal frequency should be in between cutoff frequency FL and zero dB frequency F0, We can go beyond this zero dB frequency but we will find attenuation in the output signal.

How to Reset Op-Amp integrator:
The reset of integrator can be accomplished by simply adding a switch across the feedback capacitor.

The timestamps for various topics covered in this video are as follows:
0:46 - How to use Op-Amp as an integrator (Derivation)
4:56 - Op-Amp integrator behavior on square wave input,
6:40 - Limitations (Impedance) of integrator,
8:01 - Frequency response of simple integrator,
9:25 - Solution for limitations (Practical Integrator),
11:14 - Frequency response of practical integrator,
13:47 - Example - 1,
14:56 - Example - 2,
15:50 - Example - 3,
17:42 - Example - 4.

Links for related videos on OP-Amp,
1) OP-Amp - Input and Output offset voltage
[ Ссылка ]

2) OP-Amp - Input Bias current and Input Offset current
[ Ссылка ]

3) OP-Amp - Inverting Amplifier
[ Ссылка ]

4) OP-Amp - Non-inverting Amplifier
[ Ссылка ]

5) Multistage OP-Amp or Cascaded OP-Amp
[ Ссылка ]

6) OP-Amp: Summing Amplifier (Adder)
[ Ссылка ]

7) OP-Amp: Differential Amplifier (Subtractor)
[ Ссылка ]

Music Credit:
[ Ссылка ]

Please SUBSCRIBE my You Tube channel.
"Keep Learning and Keep Growing".

свернуть