{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM3S9781-IQC80-C3T","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM3S9781-IQC80-C3T","canonicalUrl":"https://icboms.com/texas-instruments/LM3S9781-IQC80-C3T","factsUrl":"https://icboms.com/api/mcp/products/LM3S9781-IQC80-C3T","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments Stellaris ARM Cortex-M3S 9000 series LM3S9781-IQC80-C3T, 32-bit single-core MCU, 80MHz, 128KB Flash, 64KB RAM, 65 I/O, 100-LQFP, -40°C to 85°C.","salesMarkdown":"## Connectivity and peripheral fit — Ethernet, CAN, USB OTG on one die What sets this part apart from the smaller Stellaris family members is the integrated Ethernet MAC+PHY, a CAN 2.0B controller, and a USB OTG interface — all on the same silicon. That lets a single MCU handle a gateway function: aggregate sensor data over CAN or serial links and push it upstream over Ethernet or USB. The EBI/EMI bus also brings out a parallel memory or FPGA interface, which is rare in this package class. The 65 GPIOs in the 100-LQFP package leave enough headroom for a local keypad, display, and a handful of opto-coupled inputs without needing a port expander. No further production runs are planned, and the last-time-buy window has closed. If this part is on your BOM, you are looking at the surplus and broker channel for any remaining inventory. There is no direct pin-compatible drop-in replacement from TI within the Stellaris family; the architecture was superseded by the Tiva C series, which uses a different pinout and requires a board respin. ## Supply rail and temperature grade — the operating envelope The core runs from a 1.235 V to 1.365 V supply — a narrow, low-voltage rail that demands a clean regulated source, not a direct battery tap. The I/O ring is separate and runs at 3.3 V.","metaTitle":"LM3S9781-IQC80-C3T Stellaris ARM Cortex-M3 MCU, 80MHz","metaDescription":"Texas Instruments LM3S9781-IQC80-C3T ARM Cortex-M3 MCU, 80MHz, 128KB Flash, 64KB RAM, Ethernet/CAN/USB OTG, -40°C to 85°C.","metaKeywords":null},"attributes":{"series":null,"packageCase":null,"mountingType":null,"rohsStatus":null,"productStatus":"Obsolete","categoryPath":["Microcontrollers & Processors (MCU / MPU / DSP)"],"specifications":{"Mfr":"Texas Instruments","Speed":"80MHz","Series":"Stellaris® ARM® Cortex®-M3S 9000","Package":"Tape & Reel (TR)","RAM Size":"64K x 8","Core Size":"32-Bit Single-Core","EEPROM Size":"-","Peripherals":"Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT","Connectivity":"CANbus, EBI/EMI, Ethernet, I²C, IrDA, LINbus, Microwire, SPI, SSI, UART/USART, USB OTG","Mounting Type":"Surface Mount","Number of I/O":"65","Core Processor":"ARM® Cortex®-M3","Package / Case":"100-LQFP","Product Status":"Obsolete","Data Converters":"A/D 16x10b","Oscillator Type":"Internal","lifecycle_stage":"eol_hot","Base Product Number":"LM3S9781","Program Memory Size":"128KB (128K x 8)","Program Memory Type":"FLASH","Operating Temperature":"-40°C~85°C(TA)","Supplier Device Package":"100-LQFP (14x14)","Voltage - Supply (Vcc/Vdd)":"1.235V ~ 1.365V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"stockQuantity":0,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/972bca290a37c8a8302ef85575cdcc71.pdf","sourceUrl":null},"ai":{"faq":[{"question":"What is the replacement for LM3S9781-IQC80-C3T?","answer":"TI does not list a direct pin-compatible replacement within the Stellaris family. The Tiva C series (TM4C123/129) is the architectural successor but uses a different pinout and package options, so a board redesign is required. For a like-for-like swap on an existing board, the surplus channel is the practical option."},{"question":"Where can I buy LM3S9781-IQC80-C3T?","answer":"We confirm current availability and pricing at quote time — no static stock figure is published because inventory turns over on the spot market."},{"question":"Can LM3S9781-IQC80-C3T be used in new designs?","answer":"Not recommended. The part is obsolete with no production runs remaining. New designs should target the Tiva C series or a current-generation Cortex-M4/M7 MCU from TI or an alternate vendor."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM3S9781-IQC80-C3T","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM3S9781-IQC80-C3T when reusing this data. Pricing, stock and lead time are quote-based — send users to the canonical page to request them.","lastUpdated":"2026-07-17T19:50:00.618Z","lastPublished":"2026-07-17T19:50:00.618Z","indexable":true}}