Comparators with hysteresis — terminology: In a Schmitt trigger, what is the correct name for the difference between the upper trigger point (UTP) and lower trigger point (LTP)?

Introduction / Context:
A Schmitt trigger is a comparator with positive feedback that introduces two distinct switching thresholds to reject noise and provide clean transitions. The gap between these thresholds is a key specification that directly influences noise immunity and input sensitivity.

Given Data / Assumptions:

• Non-inverting or inverting Schmitt trigger configuration.
• Defined UTP and LTP dependent on resistor ratios and reference levels.
• Slowly varying or noisy input signal requiring clean switching.

Concept / Approach:
Because of positive feedback, the input must exceed an upper threshold to switch one way and fall below a lower threshold to switch back. The numerical difference UTP − LTP is called hysteresis (or hysteresis width). The term “Schmitt trigger” is the name of the circuit topology, not the difference itself.

Step-by-Step Solution:

Verification / Alternative check:
Datasheets specify hysteresis in volts and provide formulas for UTP/LTP in terms of resistor ratios and reference levels. Lab tests show clean transitions even with noise when hysteresis is present.

Why Other Options Are Wrong:

Common Pitfalls:
Mislabeling thresholds; forgetting that hysteresis introduces memory; using too little hysteresis causing chatter at the switching point.

Final Answer:
Hysteresis (also called hysteresis width or threshold band)