Operational amplifiers, when used in open-loop configuration, serve as excellent voltage comparators, distinguishing whether an input signal is higher or lower than a reference voltage. However, a standard comparator faces a critical practical limitation: noise. When a slowly varying input signal crosses the threshold, even a small amount of noise can cause the output to rapidly oscillate between the positive and negative saturation voltages ((+V_sat) and (-V_sat)). This phenomenon, known as chattering, is unacceptable in applications like motor control or digital interfacing. On page 124 of his seminal text, Op-Amps and Linear Integrated Circuits, Ramakant Gayakwad addresses this problem by introducing the Schmitt trigger, a regenerative comparator that employs positive feedback to introduce hysteresis, thereby creating a noise-immune switching circuit.
A significant portion of the text is dedicated to signal generation. It covers the design of sinusoidal oscillators (Wien-Bridge, Phase Shift) and non-sinusoidal generators (Astable and Monostable multivibrators). This section is particularly useful for those interested in function generators and timing circuits.
Since your search focuses on page 124, let’s simulate the content. In the 4th edition (Pearson Education), around page 124, the book explains the Open-Loop Frequency Response. Example Problem (similar to what you might find
Key points usually found there:
Example Problem (similar to what you might find on page 124): Given a 741 op-amp with open-loop gain of
Given a 741 op-amp with open-loop gain of 200,000 at DC and a unity-gain bandwidth of 1 MHz. If you design a non-inverting amplifier with a closed-loop gain of 100, what is its bandwidth?
Solution: Bandwidth = (Unity-gain frequency) / (Closed-loop gain) = 1 MHz / 100 = 10 kHz. when used in open-loop configuration
If you cannot access the PDF immediately, this formula and the Bode plot on page 124 are what you need to memorize.
Operational amplifiers, when used in open-loop configuration, serve as excellent voltage comparators, distinguishing whether an input signal is higher or lower than a reference voltage. However, a standard comparator faces a critical practical limitation: noise. When a slowly varying input signal crosses the threshold, even a small amount of noise can cause the output to rapidly oscillate between the positive and negative saturation voltages ((+V_sat) and (-V_sat)). This phenomenon, known as chattering, is unacceptable in applications like motor control or digital interfacing. On page 124 of his seminal text, Op-Amps and Linear Integrated Circuits, Ramakant Gayakwad addresses this problem by introducing the Schmitt trigger, a regenerative comparator that employs positive feedback to introduce hysteresis, thereby creating a noise-immune switching circuit.
A significant portion of the text is dedicated to signal generation. It covers the design of sinusoidal oscillators (Wien-Bridge, Phase Shift) and non-sinusoidal generators (Astable and Monostable multivibrators). This section is particularly useful for those interested in function generators and timing circuits.
Since your search focuses on page 124, let’s simulate the content. In the 4th edition (Pearson Education), around page 124, the book explains the Open-Loop Frequency Response.
Key points usually found there:
Example Problem (similar to what you might find on page 124):
Given a 741 op-amp with open-loop gain of 200,000 at DC and a unity-gain bandwidth of 1 MHz. If you design a non-inverting amplifier with a closed-loop gain of 100, what is its bandwidth?
Solution: Bandwidth = (Unity-gain frequency) / (Closed-loop gain) = 1 MHz / 100 = 10 kHz.
If you cannot access the PDF immediately, this formula and the Bode plot on page 124 are what you need to memorize.