{"schemaVersion":"matrix-product-facts/v1","identity":{"mpn":"LM3S5791-IQC80-C3T","brand":"Texas Instruments","brandSlug":"texas-instruments","productSlug":"LM3S5791-IQC80-C3T","canonicalUrl":"https://icboms.com/texas-instruments/LM3S5791-IQC80-C3T","factsUrl":"https://icboms.com/api/mcp/products/LM3S5791-IQC80-C3T","rawCanonicalId":null},"summary":{"shortDescription":"Texas Instruments Stellaris ARM Cortex-M3S 5000 series LM3S5791-IQC80-C3T, 32-bit single-core MCU, 80 MHz, 128 KB Flash, 64K x 8 SRAM, 72 I/O, USB OTG, CAN, 100-LQFP, -40°C to 85°C.","salesMarkdown":"## 80 MHz Cortex-M3 with USB OTG and CAN — what this part was designed for The 72 general-purpose I/O lines and 16-channel 10-bit ADC handle local sensor and actuator interfaces. There is no listed successor or pin-compatible replacement in the official record. Buyers should verify date codes and request trace documentation, particularly for moisture-sensitive 100-LQFP packages that may have been in storage beyond their floor-life window. The 80 MHz core clock is the headline performance spec. On a Cortex-M3 with a single-cycle multiply and a 3-stage pipeline, 80 MHz delivers roughly 80 DMIPS, which is enough for real-time control loops (motor FOC, PID at 10–20 kHz update rates) and moderate protocol processing (USB bulk transfers, CAN message handling). The flash wait state at 80 MHz needs to be set to at least 1 wait state per the reference manual — running at full speed with zero wait states will cause hard faults on the first branch. The 64 KB SRAM is sufficient for a single USB buffer and a few CAN message objects without external memory, but designs with large frame buffers or data logging will need the EBI/EMI interface for external SRAM or FRAM. ## Package and supply — what to check before layout The LM3S5791-IQC80-C3T is supplied in a 100-LQFP package (14x14 mm body) with a 0.5 mm pitch. The core logic runs from a 1.08 V to 1.32 V supply, while the I/O bank is powered separately — the exact I/O voltage range is not listed in this record, so the datasheet must be consulted for the VDDIO pin voltage. The 100-LQFP has an exposed pad (thermal pad) on the bottom; a via stitch to a ground plane is required to keep junction temperature under control at high I/O activity and 80 MHz switching.","metaTitle":"LM3S5791-IQC80-C3T Stellaris ARM Cortex-M3 MCU, 80 MHz","metaDescription":"LM3S5791-IQC80-C3T is an obsolete Stellaris ARM Cortex-M3 MCU with 80 MHz core, 128 KB Flash, 64 KB SRAM, USB OTG, CAN, and industrial temp range.","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":"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, 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":"LM3S5791","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)":"1.08V ~ 1.32V"}},"commercial":{"minOrderQty":null,"leadTime":null,"referencePrice":null,"priceTiers":null},"links":{"datasheetUrl":"https://cdn.icboms.com/603e2ee396c884705197257f18e9e4d3.pdf","sourceUrl":null,"alternativesUrl":"https://icboms.com/api/mcp/products/LM3S5791-IQC80-C3T/alternatives.json"},"ai":{"faq":[{"question":"Is LM3S5791-IQC80-C3T obsolete?","answer":"Yes, the LM3S5791-IQC80-C3T carries an Obsolete lifecycle status. Texas Instruments has ended production, and there is no official successor or pin-compatible replacement listed."},{"question":"What is the replacement or equivalent for LM3S5791-IQC80-C3T?","answer":"No official replacement or pin-compatible equivalent is listed in the product record. For a drop-in alternative, you would need to evaluate other Stellaris or Tiva C Series MCUs from Texas Instruments with similar peripheral sets and package options, but no direct pin-to-pin replacement is confirmed."},{"question":"Does LM3S5791-IQC80-C3T have a pin-to-pin replacement?","answer":"No pin-to-pin replacement is documented in the official records. The Stellaris family includes several 100-LQFP parts with different memory and peripheral configurations, but none is listed as a direct substitute for this order code."},{"question":"What is the speed of the LM3S5791-IQC80-C3T?","answer":"The LM3S5791-IQC80-C3T has a core speed of 80 MHz, based on the ARM Cortex-M3 processor."}],"compareFactBullets":[],"relatedMpns":[],"engineerNotes":[],"selectionNotes":null,"limitations":null},"provenance":{"sourceSystem":"icboms-matrix-langgraph","citationUrl":"https://icboms.com/texas-instruments/LM3S5791-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/LM3S5791-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}}