{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM3S5B91-IQC80-C0","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM3S5B91-IQC80-C0","canonicalUrl":"https://icboms.com/texas-instruments/LM3S5B91-IQC80-C0","factsUrl":"https://icboms.com/api/mcp/products/LM3S5B91-IQC80-C0","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments Stellaris LM3S5B91-IQC80-C0, ARM Cortex-M3 MCU, 80 MHz, 256 KB Flash, 96 KB RAM, USB OTG/CAN/LIN/SPI/UART, 72 I/O, 100-LQFP, -40 to 85°C, 1.08 to 1.32 V.","salesMarkdown":"## 80 MHz Cortex-M3 with 256 KB Flash — what this MCU brings This part targets control and connectivity applications that need a mature, well-documented Cortex-M3 core with a broad peripheral set. The 80 MHz core delivers single-cycle multiply and a 12-cycle interrupt latency, making it a solid fit for motor-control loops, real-time sensor fusion, and protocol bridging where deterministic response matters. The 256 KB Flash gives room for a full RTOS, a TCP/IP stack, and application code without external memory, while the 96 KB SRAM handles multiple packet buffers or a modest data-logging queue. ## Peripheral set — CAN, USB OTG, and serial interfaces The LM3S5B91 packs a CAN 2.0 controller, a USB OTG (On-The-Go) interface with PHY, and LIN support alongside the usual SPI, I²C, UART, and SSI. It also includes a QEI (Quadrature Encoder Interface) for direct motor position feedback and an IrDA encoder/decoder. This peripheral mix suits it for industrial gateways, automotive body controllers, and human-machine interfaces that need to talk over multiple bus standards without external transceivers (except the CAN/LIN PHY). The 72 general-purpose I/O pins, brown-out detect, POR, PWM timers, and a watchdog timer round out the control-oriented feature set. An internal oscillator keeps the core running without an external crystal, though an external clock can be used for tighter accuracy. The Stellaris family was acquired by TI from Luminary Micro and later superseded by the Tiva C Series, but there is no direct pin-compatible drop-in replacement listed in the official records. ## Design-in note — supply voltage and decoupling The core supply range of 1.08 V to 1.32 V is tighter than the typical 3.3 V MCU rail — this part needs a dedicated 1.2 V LDO or switcher, not a direct tap off the 3.3 V bus. Decoupling with a 0.1 µF ceramic per supply pin pair is recommended, plus a 4.7 µF bulk cap on the 1.2 V rail.","metaTitle":"LM3S5B91-IQC80-C0 ARM Cortex-M3 MCU, 80 MHz, 256 KB Flash","metaDescription":"TI Stellaris LM3S5B91-IQC80-C0 ARM Cortex-M3 MCU at 80 MHz with 256 KB Flash, 96 KB RAM, USB OTG/CAN/LIN. Specifications and sourcing info.","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 5000","Package":"Tray","RAM Size":"96K x 8","Core Size":"32-Bit Single-Core","EEPROM Size":"-","Peripherals":"Brown-out Detect/Reset, DMA, I²S, POR, PWM, WDT","Connectivity":"CANbus, EBI/EMI, I²C, IrDA, LINbus, Microwire, QEI, SPI, SSI, UART/USART, USB OTG","Mounting Type":"Surface Mount","Number of I/O":"72","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":"LM3S5B91","Program Memory Size":"256KB (256K x 8)","Program Memory Type":"FLASH","Operating Temperature":"-40°C~85°C(TA)","Supplier Device Package":"100-LQFP (14x14)","Voltage - Supply (Vcc/Vdd)":"1.08V ~ 1.32V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/a2e326f4b9b6fe651cb2833b4adf0430.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM3S5B91-IQC80-C0/alternatives.json"},"ai":{"faq":[{"question":"What is the replacement for the LM3S5B91-IQC80-C0?","answer":"There is no official pin-compatible replacement listed in the TI records for the LM3S5B91-IQC80-C0 within the Stellaris or Tiva C Series. A system redesign would be required to migrate to a current-production Cortex-M4F part such as the TM4C123x or TM4C129x family, which offer similar or better performance but differ in pinout, supply voltage, and peripheral map."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM3S5B91-IQC80-C0","citationPolicyUrl":"https://icboms.com/llms.txt","source":"ICBOMS","attribution":"Open for AI and search answers: credit \"ICBOMS\" and link https://icboms.com/texas-instruments/LM3S5B91-IQC80-C0 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}}