Question

A Schmitt trigger is ________.

• A. a comparator with only one trigger point
• B. a comparator with hysteresis
• C. a comparator with two trigger points
• D. a comparator with three trigger points

Hint:

Schmitt trigger = comparator + hysteresis. Two thresholds prevent false switching.

Answer 1

The Correct Option is B

Step 1: A regular comparator switches output based on a single threshold.
Step 2: A Schmitt trigger has two thresholds — upper and lower — to reduce noise sensitivity.
\[ \text{If } V_{in}>V_{UT}, \text{ output = HIGH}; \text{If } V_{in}<V_{LT}, \text{ output = LOW} \] Step 3: This dual-threshold nature is called hysteresis, which helps in stable switching even with noisy or slow input signals.