{"schemaVersion":1,"slug":"iec-bcd-to-seven-segment-decoder","name":"IEC BCD-to-seven-segment decoder","kind":"symbol","abbreviation":"BCD/7SEG","aliases":["seven-segment decoder","BCD/7-SEG coder","display decoder driver"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["IEC","Manufacturer"],"summary":"IEC coder marked BCD/7SEG converting a 4-bit BCD input into seven segment-drive outputs a to g.","description":["The BCD-to-seven-segment decoder is an X/Y coder with the qualifier BCD/7SEG, sometimes written BCD/7-SEG. Inputs are weighted 1, 2, 4 and 8 and outputs are labelled a to g for the display segments. Many devices add lamp test and blanking inputs shown with their own labels.","Seven-segment decoders appear on drawings for local numeric displays, counters and older instrument panels. The output stage type matters: many drivers have open-collector outputs intended to sink LED or lamp current, which should be shown with the open-circuit qualifier.","The symbol does not state segment current, display type (common anode or cathode) or how non-BCD codes are displayed. Those come from the device data and display selection."],"readingNotes":["Outputs a to g map to display segments.","Check output type and display common connection."],"drawingChecklist":["Label segment outputs a to g.","Show lamp test and blanking inputs where used.","Show current-limiting resistors and display wiring."],"distinction":"A BIN/OCT decoder activates one output per code; this coder activates a pattern of segments.","facts":[{"label":"Qualifier","value":"BCD/7SEG"},{"label":"Example device family","value":"BCD-to-seven-segment decoders/drivers"},{"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 BIN/7-SEG style coder designations."},{"sourceId":"s28-ti-ls47","relevance":"Manufacturer BCD-to-seven-segment decoder/driver documentation."}],"related":["iec-decade-counter","iec-binary-decoder","iec-code-converter"],"artwork":"s28-iec-bcd-to-seven-segment-decoder","publishedOn":"2026-10-28","updatedOn":"2026-10-28","provenance":"independent-public-research","symbolVariant":{"convention":"IEC","form":"X/Y coder with BCD/7SEG qualifier and segment outputs a to g","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 BCD-to-seven-segment decoder mean?","introduction":"The BCD-to-seven-segment decoder is an X/Y coder with the additional drawing mark BCD/7SEG, sometimes written BCD/7-SEG. Inputs are weighted 1, 2, 4 and 8 and outputs are labelled a to g for the display segments. Many devices add lamp test and blanking inputs shown with their own labels.","example":"Seven-segment decoders appear on drawings for local numeric displays, counters and older instrument panels. The output stage type matters: many drivers have open-collector outputs intended to sink LED or lamp current, which should be shown with the open-circuit additional drawing mark.","drawings":"The symbol does not state segment current, display type (common anode or cathode) or how non-BCD codes are displayed. Those come from the device data and display selection.","terms":[{"name":"Signal","meaning":"Electrical information passed between devices, rather than necessarily the main power supply."},{"name":"Rating","meaning":"A value stating the conditions for which equipment is specified."},{"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":"SN74LS47 BCD-to-seven-segment decoders/drivers","url":"https://www.ti.com/lit/ds/symlink/sn74ls47.pdf"}],"detail":"IEC coder marked BCD/7SEG converting a 4-bit BCD input into seven segment-drive outputs a to g. A BIN/OCT decoder activates one output per code; this coder activates a pattern of segments.","profileId":"reviewed-symbol-20261028"},"url":"https://eloragrid.ai/symbols/iec-bcd-to-seven-segment-decoder","illustration":{"url":"https://eloragrid.ai/tools/electrical-library/illustrations/iec-bcd-to-seven-segment-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":"Lists BIN/7-SEG style coder designations."},{"id":"s28-ti-ls47","title":"SN74LS47 BCD-to-seven-segment decoders/drivers","publisher":"Texas Instruments","url":"https://www.ti.com/lit/ds/symlink/sn74ls47.pdf","type":"manufacturer","scope":"Device documentation for BCD-to-seven-segment decoder/drivers.","checkedOn":"2026-10-28","reuse":"link-only","relevance":"Manufacturer BCD-to-seven-segment decoder/driver documentation."}]}