COMP
Voltage comparator
Compares two analogue input voltages and produces the documented output-state indication.
Schematic
Symbols · COMP-H
Op-amp comparator with hysteresis
Comparator or op-amp with positive feedback to the plus input, creating two switching thresholds.
In plain English
What does Op-amp comparator with hysteresis mean?
Adding a resistor from the output to the non-inverting input of a comparator gives positive feedback, so the switching threshold depends on the current output state. The result is hysteresis: the circuit switches at one level on a rising input and a lower level on a falling input, rejecting noise near the threshold.
A simple example
This circuit is used for level detection from slow analogue signals such as temperature, battery voltage or tank level. The drawing should state both thresholds, or the resistor values and reference from which they are derived.
What the drawings help you do
The circuit symbol does not show the thresholds directly and they depend on output swing, so a part with rail-to-rail or open-collector output changes the calculation.
This particular reference
Comparator or op-amp with positive feedback to the plus input, creating two switching thresholds. An op-amp amplifier uses negative feedback to the minus input; this circuit uses positive feedback.
- Signal
- Electrical information passed between devices, rather than necessarily the main power supply.
- Rating
- A value stating the conditions for which equipment is specified.
- Schematic
- A drawing showing function and connections rather than physical appearance.
Read the source: TLV3201 — voltage comparison · University tutorials: amplifier configurations and signal processing
Schematic · COMP-H
What it represents
Adding a resistor from the output to the non-inverting input of a comparator gives positive feedback, so the switching threshold depends on the current output state. The result is hysteresis: the circuit switches at one level on a rising input and a lower level on a falling input, rejecting noise near the threshold.
This circuit is used for level detection from slow analogue signals such as temperature, battery voltage or tank level. The drawing should state both thresholds, or the resistor values and reference from which they are derived.
The circuit symbol does not show the thresholds directly and they depend on output swing, so a part with rail-to-rail or open-collector output changes the calculation.
How to read it
- Feedback to the plus input indicates hysteresis, not gain.
- Thresholds depend on output swing.
Information to show or reference
- Show the positive feedback resistor and reference.
- State both switching thresholds.
- Show the output pull-up if the comparator is open collector.
A distinction that matters
An op-amp amplifier uses negative feedback to the minus input; this circuit uses positive feedback.
Sources you can follow
These public references support the explanation and provide further detail. Their graphics and downloadable files remain with their publishers.
TLV3201 — voltage comparison
Manufacturer comparator documentation.
University tutorials: amplifier configurations and signal processing
Public tutorial material on comparator and feedback configurations.
About this graphic
This illustration was authored independently by Elora Grid to explain the concept. It is not reproduced from a customer drawing, an official standard graphic or a manufacturer CAD file. Its correspondence to an exact IEC or IEEE symbol identifier has not been certified.
SVG and DXF downloads contain this original artwork. DXF uses unscaled drawing units; a GA envelope supplies no product dimensions, clearances or fabrication information. Original artwork is available under CC BY 4.0. Third-party references retain their own terms.
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