CHAPTER 23 (4): OPERATIONAL AMPLIFIERS

What are the three major types of Op-Amp Comparators?

Zero level comparator, Non-zero level comparator, Comparator with hysteresis.

What is the function of a zero level comparator?

It compares the input signal with zero voltage level.

What does hysteresis do in a comparator circuit?

It reduces sensitivity to noise by applying positive feedback, creating upper and lower trigger points.

What is VUTP in a comparator with hysteresis?

The upper trigger point where the output voltage switches to its maximum positive voltage.

What happens when the input voltage exceeds VUTP?

The output voltage drops to its negative maximum, -Vo(sat).

What is the significance of VLTP in a hysteresis comparator?

It is the lower trigger point where the output switches back to maximum positive voltage.

How is hysteresis defined in a comparator circuit?

By the difference between the upper trigger point (VUTP) and lower trigger point (VLTP), VHYS = VUTP - VLTP.

What configuration do op-amps operate in when used as comparators?

Open-loop configuration.

What can cause erratic switching states in a comparator?

Unwanted voltage fluctuations (noise) on the input line.

What is the primary use of a comparator circuit?

To compare amplitudes of one voltage with another and determine if an input voltage exceeds a certain level.