{"schemaVersion":1,"slug":"iec-magnitude-comparator","name":"IEC magnitude comparator (COMP)","kind":"symbol","abbreviation":"COMP","aliases":["IEC digital comparator","COMP element","P>Q comparator"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"IEC COMP element comparing two binary words P and Q, with outputs for P>Q, P=Q and P<Q.","description":["The IEC magnitude comparator is marked COMP. Its inputs are grouped as word P and word Q with binary weights, and its outputs are labelled P>Q, P=Q and P<Q. Cascading inputs carry the same labels in a separate group so that comparators can be chained for longer words.","Digital comparators appear in set-point logic, address matching and limit checking. A reviewer should confirm the bit order of P and Q, because a swapped weight produces a comparison that is correct only for some values.","The symbol does not indicate whether the comparison is for signed or unsigned numbers. Standard devices compare unsigned binary."],"readingNotes":["Check bit weights on both words.","Cascade inputs are needed for words longer than one device."],"drawingChecklist":["Group and weight the P and Q inputs.","Label all three outputs.","Show cascade connections."],"distinction":"An analogue voltage comparator compares two voltages, not binary words.","facts":[{"label":"Qualifier","value":"COMP"},{"label":"Outputs","value":"P>Q, P=Q, P<Q"},{"label":"Artwork scope","value":"Original educational illustration; consult the applicable standard and the selected device documentation for the exact graphic"}],"references":[{"sourceId":"s28-ti-ieee91-logic-symbols","relevance":"Lists COMP as the magnitude comparator qualifier."},{"sourceId":"pub-electronics-ti-hc85","relevance":"Magnitude comparator documentation."}],"related":["digital-magnitude-comparator","voltage-comparator","iec-arithmetic-logic-unit"],"artwork":"s28-iec-magnitude-comparator","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Rectangular element with COMP qualifier and P, Q input groups","reference":"Qualifying-symbol and dependency conventions as explained in TI's public overview of IEEE Std 91-1984, which incorporates IEC 617-12 work. Independent educational drawing; not certified IEC geometry or an IEC database identifier. The counterpart is the matching functional concept; no equivalence of every detailed standard graphic is asserted.","counterpart":"digital-magnitude-comparator"},"plainEnglish":{"title":"What does IEC magnitude comparator (COMP) mean?","introduction":"The IEC magnitude comparator is marked COMP. Its inputs are grouped as word P and word Q with binary weights, and its outputs are labelled P>Q, P=Q and P<Q. Cascading inputs carry the same labels in a separate group so that comparators can be chained for longer words.","example":"Digital comparators appear in set-point logic, address matching and limit checking. A reviewer should confirm the bit order of P and Q, because a swapped weight produces a comparison that is correct only for some values.","drawings":"The symbol does not indicate whether the comparison is for signed or unsigned numbers. Standard devices compare unsigned binary.","terms":[{"name":"Signal","meaning":"Electrical information passed between devices, rather than necessarily the main power supply."},{"name":"Schematic","meaning":"A drawing showing function and connections rather than physical appearance."}],"diagram":"flow","steps":["Identify the device and form","Read the connections and state","Check the equipment reference"],"caption":"A guide to reading this reference. The original symbol illustration and its drawing notes appear below; these boxes are not a wiring diagram.","sources":[{"label":"Overview of IEEE Standard 91-1984: explanation of logic symbols (SDYZ001A)","url":"https://www.ti.com/lit/ml/sdyz001a/sdyz001a.pdf"},{"label":"CD74HC85 — digital magnitude comparators","url":"https://www.ti.com/product/CD74HC85"}],"detail":"IEC COMP element comparing two binary words P and Q, with outputs for P>Q, P=Q and P<Q. An analogue voltage comparator compares two voltages, not binary words.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-magnitude-comparator","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-magnitude-comparator.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"s28-ti-ieee91-logic-symbols","title":"Overview of IEEE Standard 91-1984: explanation of logic symbols (SDYZ001A)","publisher":"Texas Instruments","url":"https://www.ti.com/lit/ml/sdyz001a/sdyz001a.pdf","type":"manufacturer","scope":"Public explanation of rectangular logic symbols, general qualifiers, input and output qualifiers, dependency notation, bistable elements and coders, consistent with IEC 617-12 work.","checkedOn":"2026-10-28","reuse":"link-only","relevance":"Lists COMP as the magnitude comparator qualifier."},{"id":"pub-electronics-ti-hc85","title":"CD74HC85 — digital magnitude comparators","publisher":"Texas Instruments","url":"https://www.ti.com/product/CD74HC85","type":"manufacturer","scope":"Public device-function and terminal documentation used as an example of digital magnitude comparators. Example part numbers are manufacturer identifiers, not IEC/IEEE symbol IDs. Device ratings, pin numbering and availability remain in the selected product documentation.","checkedOn":"2026-10-14","reuse":"link-only","relevance":"Magnitude comparator documentation."}]}