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Texas Instruments LM3S5D91-IQC80-A2T — Microcontrollers & Processors (MCU / MPU / DSP)

LM3S5D91-IQC80-A2T Stellaris ARM Cortex-M3 MCU, 80 MHz, 512 KB Flash

MPNLM3S5D91-IQC80-A2T
Obsolete

Texas Instruments Stellaris ARM Cortex-M3S 5000 series 32-bit MCU, LM3S5D91-IQC80-A2T, 80 MHz, 512 KB Flash, 96 KB RAM, CANbus, USB OTG, 100-LQFP, -40 to 85°C.

Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

LM3S5D91-IQC80-A2T specifications
ParameterValue
SeriesStellaris® ARM® Cortex®-M3S 5000
MountingSurface Mount
Oscillator typeInternal
Program memory typeFLASH
Voltage - supply (Vcc (Vdd))3V ~ 3.6V
Operating temperature-40°C~85°C(TA)
Speed80MHz
PackageTape & Reel (TR)
RAM size96K x 8
Core size32-Bit Single-Core
PeripheralsBrown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
ConnectivityCANbus, EBI/EMI, I²C, IrDA, LINbus, Microwire, QEI, SPI, SSI, UART/USART, USB OTG
Number of i (O)72
Core processorARM® Cortex®-M3
Case100-LQFP
Data convertersA/D 16x12b
Program memory size512KB (512K x 8)

Product details

What this Stellaris MCU brings to the board

The LM3S5D91-IQC80-A2T is a 32-bit ARM Cortex-M3 microcontroller from the Stellaris 5000 series, clocked at 80 MHz. It has 512 KB Flash and 96 KB RAM.

512 KB Flash — firmware fit and field updates

The Flash is programmable in-system, so field updates are possible over the USB or CAN link. No EEPROM on-chip; if you need non-volatile parameter storage, budget a few Flash pages for emulated EEPROM or add an external serial EEPROM.

Connectivity and I/O lineup

This MCU includes CANbus, USB OTG, and serial interfaces (UART, SPI, I²C, SSI, Microwire, IrDA, LIN). The 72 GPIOs can drive a keypad-and-LED panel plus a parallel bus.

The LM3S5D91-IQC80-A2T is officially obsolete per the manufacturer. No last-time-buy window remains open. There is no direct pin-compatible drop-in from TI's current portfolio; the Stellaris line was absorbed into the Tiva C series, but those parts differ in peripheral map and require firmware porting. If you need a drop-in second source, check the LM3S5D91's siblings in the same 100-LQFP package — the base part number LM3S5D91 covers multiple speed and temperature grades, but all are now obsolete.

Frequently asked questions

What is the closest pin-compatible alternative to LM3S5D91-IQC80-A2T?

There is no direct pin-compatible replacement from TI's current portfolio. The Tiva C series (e.g., TM4C123) is the architectural successor but differs in peripheral map and requires firmware porting. Siblings within the LM3S5D91 base part number (different speed/temp grades) share the same 100-LQFP footprint but are also obsolete.

What is LM3S5D91-IQC80-A2T's listed speed?

The core runs at 80 MHz.

What series is LM3S5D91-IQC80-A2T from?

It is part of the Stellaris ARM Cortex-M3S 5000 series from Texas Instruments.

What compliance documentation does TI provide for LM3S5D91-IQC80-A2T?

The part is RoHS compliant as standard for TI's commercial offerings. Specific REACH and conflict minerals declarations are available from TI's compliance portal for the base part number LM3S5D91.