{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"BQ27421YZFT-G1B","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"BQ27421YZFT-G1B","canonicalUrl":"https://icboms.com/texas-instruments/BQ27421YZFT-G1B","factsUrl":"https://icboms.com/api/mcp/products/BQ27421YZFT-G1B","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments Impedance Track™ series, BQ27421YZFT-G1B, single-cell Li-ion battery fuel gauge with I²C interface, 9-DSBGA package, -40°C to 85°C operating range.","salesMarkdown":"## Single-cell Li-ion fuel gauge with Impedance Track™ The BQ27421YZFT-G1B is a single-cell Lithium Ion battery monitor from Texas Instruments' Impedance Track™ series. It reports remaining capacity, state-of-charge, and voltage over an I²C interface, with the Impedance Track™ algorithm learning the battery's impedance in real time for improved accuracy over simple voltage-based gauges. ## I²C host interface and single-cell constraint The I²C bus is the only communication channel — the host reads gauge data on demand, no interrupt pin. The single-cell requirement is non-negotiable: this part monitors exactly one series cell. For 2-to-4-cell packs, the BQ2084DBT-V143 uses an SMBus interface and supports multiple cells, but its temperature range stops at 85°C. ## Active production, 9-DSBGA package The 9-UFBGA, DSBGA package with 0.50 mm pitch demands careful PCB layout — the 9-DSBGA footprint is small, so ensure the solder mask and stencil aperture match the TI recommended land pattern.","metaTitle":"BQ27421YZFT-G1B Battery Fuel Gauge IC – Texas Instruments","metaDescription":"Active-production single-cell Li-ion fuel gauge with I²C interface, Impedance Track™ algorithm, 9-DSBGA package, -40°C to 85°C range. Sourced per RFQ.","metaKeywords":null},"attributes":{"series":"Impedance Track™","packageCase":null,"mountingType":null,"rohsStatus":"ROHS3 Compliant","productStatus":"Active","categoryPath":["Power Management (PMIC / Gate Driver)"],"specifications":{"Mfr":"Texas Instruments","Series":"Impedance Track™","Package":"Tape & Reel (TR); Cut Tape (CT)","Function":"Battery Monitor","Interface":"I²C","Mounting Type":"Surface Mount","Package / Case":"9-UFBGA, DSBGA","Product Status":"Active","Number of Cells":"1","lifecycle_stage":"eol_hot","Fault Protection":"-","Battery Chemistry":"Lithium Ion","Base Product Number":"BQ27421","Operating Temperature":"-40°C~85°C(TA)","Supplier Device Package":"9-DSBGA"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":"$3.0800","priceTiers":[{"qty":1,"price":"$3.08000","currency":"USD"},{"qty":10,"price":"$2.77000","currency":"USD"},{"qty":25,"price":"$2.61280","currency":"USD"},{"qty":100,"price":"$2.22620","currency":"USD"},{"qty":250,"price":"$2.09032","currency":"USD"},{"qty":500,"price":"$1.82904","currency":"USD"},{"qty":1250,"price":"$1.51548","currency":"USD"},{"qty":2500,"price":"$1.47900","currency":"USD"}]},"links":{"datasheetUrl":"https://cdn.icboms.com/21a7be246ef4b65e44fc22133d69db26.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/BQ27421YZFT-G1B/alternatives.json"},"ai":{"faq":[{"question":"Is BQ27421YZFT-G1B compatible with 3.7V Li-ion batteries?","answer":"Yes. The BQ27421YZFT-G1B is designed for single-cell Lithium Ion batteries, which have a nominal voltage of 3.6–3.7 V. The gauge monitors the cell voltage directly through its Vbat pin."},{"question":"What is the difference between BQ27421 and BQ27426 fuel gauge?","answer":"The BQ27421 and BQ27426 are both single-cell Impedance Track™ gauges from Texas Instruments. The BQ27426 adds a low-power sleep mode and a different I²C address, but the BQ27421 is the more widely stocked variant. Confirm the exact firmware configuration — the BQ27421YZFT-G1B is pre-programmed for LiCoO2 chemistry."},{"question":"What is the replacement for BQ27421YZFT-G1B if it goes obsolete?","answer":"As of the current lifecycle status, the BQ27421YZFT-G1B is Active with no announced end-of-life. Texas Instruments has not published a direct successor. For automotive or extended-temperature applications, the BQ79612PAPRQ1 is a functional alternative but requires a different interface (SPI/UART) and has a different package."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/BQ27421YZFT-G1B","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/BQ27421YZFT-G1B 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}}