{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"TL431QPK","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"TL431QPK","canonicalUrl":"https://icboms.com/texas-instruments/TL431QPK","factsUrl":"https://icboms.com/api/mcp/products/TL431QPK","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments TL431QPK adjustable shunt voltage reference, ±2.2% tolerance, 2.495V min output, 100 mA cathode current, SOT-89-3 surface mount, -40°C to 125°C operating temperature.","salesMarkdown":"The shunt regulator topology means it sinks current from a supply rail through a series resistor to maintain the reference voltage at the REF pin. This Q-grade variant carries a ±2.2% initial tolerance on the 2.495 V internal reference, which is tighter than the standard ±2.5% grade and looser than the ±1% A-grade. For a 5 V output using a 1% feedback divider, the total regulation band at 25°C works out to roughly ±50 mV before temperature drift. The SOT-89-3 package (TO-243AA) is a medium-power surface-mount package with a large collector tab for heat sinking. The base product number TL431 spans dozens of package and tolerance variants across multiple manufacturers. Pin compatibility should be verified against the target footprint before substituting. The 100 mA cathode current rating sets the maximum load the shunt can sink while regulating. In a typical feedback application for a switching power supply, the TL431QPK draws about 1 mA quiescent current through the cathode, leaving 99 mA of headroom for driving the optocoupler LED and bias network. That is plenty for most flyback and forward-converter designs. The 36 V maximum output voltage means this part can regulate rails up to 36 V, covering 24 V industrial supplies, 12 V automotive buses, and 5 V logic rails with margin. The 2.495 V minimum output is the bandgap reference voltage itself — any output below that is not possible without an external negative rail. The SOT-89-3 package's thermal resistance junction-to-ambient is typically around 55°C/W with adequate copper — at 100 mA cathode current and 36 V drop (3.6 W), the part would exceed its maximum junction temperature, so the cathode current and voltage drop must be derated together.","metaTitle":"TL431QPK Shunt Voltage Reference, Adjustable, ±2.2%","metaDescription":"TL431QPK adjustable shunt voltage reference, 2.495V min output, 100 mA cathode current, ±2.2% tolerance, -40°C to 125°C, SOT-89-3.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Active","categoryPath":["Analog & Data Acquisition"],"specifications":{"Mfr":"Texas Instruments","Series":"-","Package":"Tape & Reel (TR); Cut Tape (CT)","Tolerance":"±2.2%","Output Type":"Adjustable","Mounting Type":"Surface Mount","Package / Case":"TO-243AA","Product Status":"Active","Reference Type":"Shunt","Voltage - Input":"-","lifecycle_stage":"eol_hot","Current - Output":"100 mA","Current - Supply":"-","Current - Cathode":"1 mA","Base Product Number":"TL431","Noise - 0.1Hz to 10Hz":"-","Noise - 10Hz to 10kHz":"-","Operating Temperature":"-40°C~125°C(TA)","Voltage - Output (Max)":"36 V","Supplier Device Package":"SOT-89-3","Temperature Coefficient":"-","Voltage - Output (Min/Fixed)":"2.495V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$0.4600","priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/2e8567ad04842692d5fb8309c69e90b6.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/TL431QPK/alternatives.json"},"ai":{"faq":[{"question":"What is the tolerance of TL431QPK?","answer":"The TL431QPK has a ±2.2% initial tolerance on the 2.495 V internal reference. This is the Q-grade variant, which sits between the standard ±2.5% grade and the precision ±1% A-grade in the TL431 family."},{"question":"What is the difference between TL431QPK and TL431A?","answer":"The primary difference is the tolerance grade. The TL431QPK carries a ±2.2% tolerance, while the TL431A is typically a ±1% grade. The QPK suffix also specifies the SOT-89-3 package, whereas the A-grade is available in multiple packages including TO-92 and SOIC-8. The operating temperature range and electrical ratings (100 mA cathode current, 36 V max output) are the same across the family."},{"question":"Is TL431QPK RoHS compliant?","answer":"The evidence does not explicitly list RoHS compliance status for this order code. The TL431 family from Texas Instruments is generally RoHS-compliant in lead-free packages, but confirm the specific date code and lot against the manufacturer's RoHS certificate before accepting into a RoHS-required production line."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/TL431QPK","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/TL431QPK when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-22T18:03:28.771Z","lastPublished":"2026-07-22T18:03:28.771Z","indexable":true}}