{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"TMP421AQDCNTQ1","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"TMP421AQDCNTQ1","canonicalUrl":"https://icboms.com/texas-instruments/TMP421AQDCNTQ1","factsUrl":"https://icboms.com/api/mcp/products/TMP421AQDCNTQ1","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments TMP421AQDCNTQ1, Automotive AEC-Q100, digital temperature sensor, local/remote, 12-bit, I²C/SMBus, SOT-23-8, ±1.5°C accuracy.","salesMarkdown":"## What the accuracy numbers mean for a thermal management loop The TMP421AQDCNTQ1 reports local die temperature and a remote diode-junction temperature over a single I²C/SMBus interface, with 12-bit resolution giving 0.0625°C per LSB. The remote channel is tighter at ±1°C in the 15°C–85°C window, but degrades to ±5°C at the extremes. For a closed-loop fan controller or overtemperature shutdown, the remote accuracy in the normal operating band is the figure that governs the trip threshold margin — the ±5°C at -40°C or 125°C is a survival spec, not a control spec. An engine ECU or transmission controller that sees 105°C on a hot day still has margin before the silicon's absolute maximum junction temperature. ## Supply tolerance and power-up sequencing The part powers up in shutdown mode by default, drawing minimal current until the host sends a one-shot conversion command or a programmable limit is set — this avoids a current spike on a cold-start rail that is still ramping. The SOT-23-8 package (2.9 mm × 1.6 mm body, 0.65 mm pitch) fits a standard four-layer board with one via per signal. The exposed die attach pad on the bottom is not a thermal pad — it is the ground connection, so the PCB copper under the part should be a solid ground plane pour, not a split island. ## Active production and supply posture ROHS3 compliant per the manufacturer.","metaTitle":"TMP421AQDCNTQ1 Texas Instruments Temp Sensor, ±1.5°C","metaDescription":"Texas Instruments TMP421AQDCNTQ1 digital temperature sensor, ±1.5°C local accuracy, I2C/SMBus, AEC-Q100, SOT-23-8. Active production. Quoted per RFQ.","metaKeywords":null},"attributes":{"series":"Automotive, AEC-Q100","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Discrete Semiconductors"],"specifications":{"Series":"Automotive, AEC-Q100","Package":"Tape & Reel (TR); Cut Tape (CT)","Features":"One-Shot, Output Switch, Programmable Limit, Shutdown Mode","Resolution":"12 b","Output Type":"I²C/SMBus","Sensor Type":"Digital, Local/Remote","Mounting Type":"Surface Mount","Package / Case":"SOT-23-8","Test Condition":"15°C ~ 85°C (-40°C ~ 125°C) Local, 15°C ~ 85°C (-40°C ~ 125°C) Remote","lifecycle_stage":"eol_hot","Voltage - Supply":"2.7V ~ 5.5V","Operating Temperature":"-40°C ~ 125°C","Supplier Device Package":"SOT-23-8","Accuracy - Highest (Lowest)":"±1.5°C (±2.5°C) Local , ±1°C (±5°C) Remote","Sensing Temperature - Local":"-40°C ~ 127°C","Sensing Temperature - Remote":"-40°C ~ 127°C"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$2.4","stockQuantity":0,"priceTiers":[{"qty":1,"price":"$2.40000","currency":"USD"},{"qty":10,"price":"$2.16000","currency":"USD"},{"qty":25,"price":"$2.03800","currency":"USD"},{"qty":100,"price":"$1.73620","currency":"USD"},{"qty":250,"price":"$1.63028","currency":"USD"},{"qty":500,"price":"$1.42650","currency":"USD"},{"qty":1250,"price":"$1.18195","currency":"USD"},{"qty":2500,"price":"$1.15350","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/8865b118aa4b1801e3bc6f7946286599.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the local temperature accuracy of TMP421AQDCNTQ1?","answer":"The remote channel is ±1°C in the 15°C–85°C band, ±5°C at the extremes."},{"question":"What package does TMP421AQDCNTQ1 come in?","answer":"SOT-23-8, 8-pin surface-mount package. Also available in Tape & Reel (TR) or Cut Tape (CT) options."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/TMP421AQDCNTQ1","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/TMP421AQDCNTQ1 when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-08-11T15:49:49.435Z","lastPublished":"2026-08-11T15:49:49.435Z","indexable":true}}