{"schemaVersion":1,"slug":"phase-locked-loop","name":"Phase-locked loop","kind":"symbol","abbreviation":"PLL","aliases":["phase locked loop","frequency tracking loop"],"category":"logic-signals","drawingTypes":["Schematic"],"referenceFamilies":["Manufacturer"],"summary":"Controls an oscillator through a phase-comparison feedback arrangement to follow the documented reference.","description":["Controls an oscillator through a phase-comparison feedback arrangement to follow the documented reference.","On a schematic, identify the reference input, phase detector, loop filter and VCO control and trace the oscillator output, lock indication and feedback divider. Keep the component tag and signal/reference names consistent across the control drawing, terminal schedule and device documentation.","A PLL is a closed control loop; a VCO alone has no phase-comparison feedback function.","The preview is an independently drawn educational functional reference. Add the selected component’s actual power pins, terminal numbers, timing or analogue reference details when producing a construction drawing."],"readingNotes":["Identify the reference input, phase detector, loop filter and VCO control.","Trace the oscillator output, lock indication and feedback divider."],"drawingChecklist":["Label the reference input, phase detector, loop filter and VCO control.","Cross-reference the oscillator output, lock indication and feedback divider.","Add the selected device or circuit documentation revision, power/reference connections and project signal convention."],"distinction":"A PLL is a closed control loop; a VCO alone has no phase-comparison feedback function.","facts":[{"label":"Common schematic mnemonic","value":"PLL — descriptive only; project/device documentation defines reference designations."},{"label":"Terminal / interface focus","value":"The reference input, phase detector, loop filter and VCO control"},{"label":"Artwork scope","value":"Original educational functional/circuit reference; not a selected product pinout."}],"references":[{"sourceId":"pub-electronics-ti-cd4046","relevance":"Public primary manufacturer documentation establishes the component function or circuit/topology relationship. Preview geometry and drafting explanations are independently authored."}],"related":["voltage-controlled-oscillator","plc-io"],"artwork":"electronics-logic-pll","publishedOn":"2026-10-14","updatedOn":"2026-10-14","provenance":"independent-public-research","url":"https://eloragrid.ai/symbols/phase-locked-loop","illustration":{"url":"https://eloragrid.ai/library/illustrations/phase-locked-loop.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-ti-cd4046","title":"CD4046B — phase-locked loops and voltage-controlled oscillators","publisher":"Texas Instruments","url":"https://www.ti.com/product/CD4046B","type":"manufacturer","scope":"Public device-function and terminal documentation used as an example of phase-locked loops and voltage-controlled oscillators. 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":"Public primary manufacturer documentation establishes the component function or circuit/topology relationship. Preview geometry and drafting explanations are independently authored."}]}