{"schemaVersion":1,"slug":"iec-binary-decoder","name":"IEC binary decoder (X/Y coder)","kind":"symbol","abbreviation":"BIN/OCT","aliases":["IEC code converter decoder","BIN/OCT decoder","X/Y coder element"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"IEC coder marked BIN/OCT or similar, converting a binary input code into one active output.","description":["IEC coders use the general qualifier X/Y, where X is the input code and Y is the output code. A three-to-eight-line decoder is therefore marked BIN/OCT, with input weights 1, 2 and 4 and outputs numbered 0 to 7. Enable inputs are often combined with an & element in the common-control area.","Decoders select one of several devices, relays or indicator lines from a binary code. A drawing should keep the output numbers so a reviewer can confirm that, for example, input code 5 activates output 5.","The qualifier says nothing about output polarity; polarity triangles at outputs show active-low outputs, which are common on decoder devices."],"readingNotes":["X/Y gives input and output codes.","Check output polarity marks before reading the truth table."],"drawingChecklist":["State the code pair, such as BIN/OCT.","Show input weights.","Mark active-low outputs."],"distinction":"A BCD/7SEG coder produces segment drive patterns, not one-of-n outputs.","facts":[{"label":"Qualifier","value":"X/Y, for example BIN/OCT"},{"label":"Outputs","value":"One-of-n selection"},{"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":"X/Y coder qualifier and coder examples."},{"sourceId":"pub-electronics-ti-hc138","relevance":"Binary decoder and demultiplexer documentation."}],"related":["binary-decoder-demultiplexer","iec-code-converter","iec-priority-encoder"],"artwork":"s28-iec-binary-decoder","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"Rectangular coder with X/Y qualifier such as BIN/OCT","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":"binary-decoder-demultiplexer"},"plainEnglish":{"title":"What does IEC binary decoder (X/Y coder) mean?","introduction":"IEC coders use the general additional drawing mark X/Y, where X is the input code and Y is the output code. A three-to-eight-line decoder is therefore marked BIN/OCT, with input weights 1, 2 and 4 and outputs numbered 0 to 7. Enable inputs are often combined with an & element in the common-control area.","example":"Decoders select one of several devices, relays or indicator lines from a binary code. A drawing should keep the output numbers so a reviewer can confirm that, for example, input code 5 activates output 5.","drawings":"The additional drawing mark says nothing about output polarity; polarity triangles at outputs show active-low outputs, which are common on decoder devices.","terms":[{"name":"Coil","meaning":"A wound conductor that can produce a magnetic field when energised."},{"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":"SN74HC138 — binary decoding and demultiplexing","url":"https://www.ti.com/lit/ds/symlink/sn74hc138.pdf"}],"detail":"IEC coder marked BIN/OCT or similar, converting a binary input code into one active output. A BCD/7SEG coder produces segment drive patterns, not one-of-n outputs.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-binary-decoder","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-binary-decoder.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":"X/Y coder qualifier and coder examples."},{"id":"pub-electronics-ti-hc138","title":"SN74HC138 — binary decoding and demultiplexing","publisher":"Texas Instruments","url":"https://www.ti.com/lit/ds/symlink/sn74hc138.pdf","type":"manufacturer","scope":"Public device-function and terminal documentation used as an example of binary decoding and demultiplexing. 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":"Binary decoder and demultiplexer documentation."}]}