{"schemaVersion":1,"slug":"iec-active-low-output-indicator","name":"IEC polarity indicator at output (active-low output)","kind":"symbol","abbreviation":"POL-OUT","aliases":["output polarity triangle","active-low output mark","polarity indicator output"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"Triangle on an output lead meaning the internal active state drives the output to a low level.","description":["At an output, the polarity indicator triangle means the internal 1 state produces an external L level. It is the level-based counterpart of output negation and is used on device symbols for active-low interrupt, ready or fault outputs.","When an active-low output drives an active-low input, the two triangles show directly that the signal is asserted low throughout, which avoids the double-negation reading needed with circles. This makes signal names with a low-active suffix line up with the graphic.","The triangle does not state the output drive type. An active-low open-drain output also needs the open-circuit qualifier inside the outline."],"readingNotes":["Read the output as asserted when low.","Check for an open-circuit qualifier as well."],"drawingChecklist":["Draw the triangle on the output line at the outline edge.","Name the net to show low-active sense.","Add any output-type qualifier inside the outline."],"distinction":"An output negation circle has the same meaning in positive logic but depends on the declared convention.","facts":[{"label":"Meaning","value":"Internal 1 produces L level"},{"label":"Typical pins","value":"Interrupt, fault, ready outputs"},{"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":"Polarity indicator at outputs."}],"related":["iec-logic-output-negation","iec-active-low-input-indicator","iec-open-circuit-output-l-type"],"artwork":"s28-iec-active-low-output-indicator","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Right-angled triangle on the output line next to the outline","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."},"plainEnglish":{"title":"What does IEC polarity indicator at output (active-low output) mean?","introduction":"At an output, the polarity indicator triangle means the internal 1 state produces an external L level. It is the level-based counterpart of output negation and is used on device symbols for active-low interrupt, ready or fault outputs.","example":"When an active-low output drives an active-low input, the two triangles show directly that the signal is asserted low throughout, which avoids the double-negation reading needed with circles. This makes signal names with a low-active suffix line up with the graphic.","drawings":"The triangle does not state the output drive type. An active-low open-drain output also needs the open-circuit additional drawing mark inside the outline.","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"}],"detail":"Triangle on an output lead meaning the internal active state drives the output to a low level. An output negation circle has the same meaning in positive logic but depends on the declared convention.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-active-low-output-indicator","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-active-low-output-indicator.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":"Polarity indicator at outputs."}]}