{"schemaVersion":1,"slug":"varactor-diode","name":"Varactor diode","kind":"symbol","abbreviation":"VAR","aliases":["varicap","tuning diode","voltage-variable capacitance diode"],"category":"electronics-components","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"A reverse-biased diode whose junction capacitance is used as a voltage-controlled circuit element.","description":["A reverse-biased diode whose junction capacitance is used as a voltage-controlled circuit element.","On a schematic, identify the tuning bias, cathode orientation and RF node and trace the tuned or phase-control circuit. Keep the component tag and signal/reference names consistent across the control drawing, terminal schedule and device documentation.","A varactor uses junction capacitance under reverse bias; it is not an adjustable mechanical capacitor.","Terminal letters describe electrical roles, not package pin numbers. Check the selected public datasheet for the actual pin assignment, polarity and any internally connected terminals before completing the drawing."],"readingNotes":["Identify the tuning bias, cathode orientation and RF node.","Trace the tuned or phase-control circuit."],"drawingChecklist":["Label the tuning bias, cathode orientation and RF node.","Cross-reference the tuned or phase-control circuit.","Add the selected device or circuit documentation revision, power/reference connections and project signal convention."],"distinction":"A varactor uses junction capacitance under reverse bias; it is not an adjustable mechanical capacitor.","facts":[{"label":"Common schematic mnemonic","value":"VAR — descriptive only; project/device documentation defines reference designations."},{"label":"Terminal / interface focus","value":"The tuning bias, cathode orientation and RF node"},{"label":"Artwork scope","value":"Original educational component glyph; not a certified standard graphic or package pinout."}],"references":[{"sourceId":"pub-electronics-nxp-varactor","relevance":"Public primary manufacturer documentation establishes the component function or circuit/topology relationship. Preview geometry and drafting explanations are independently authored."}],"related":["adjustable-capacitor","diode"],"artwork":"electronics-diode-varactor","publishedOn":"2026-10-14","updatedOn":"2026-10-14","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/varactor-diode","illustration":{"url":"https://eloragrid.ai/library/illustrations/varactor-diode.svg","scope":"Original educational concept; not an official standard graphic or product footprint","license":"https://creativecommons.org/licenses/by/4.0/"},"sources":[{"id":"pub-electronics-nxp-varactor","title":"BB181 variable-capacitance diode documentation","publisher":"NXP Semiconductors","url":"https://www.nxp.com/docs/en/data-sheet/BB181.pdf","type":"manufacturer","scope":"Public historical component reference for a variable-capacitance diode, with anode/cathode roles and tuning applications. Used for terminology, not current product availability or a design recommendation.","checkedOn":"2026-10-14","reuse":"link-only","relevance":"Public primary manufacturer documentation establishes the component function or circuit/topology relationship. Preview geometry and drafting explanations are independently authored."}]}