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Texas Instruments LM3S9B81-IQC80-C5 — Microcontrollers & Processors (MCU / MPU / DSP)

Texas Instruments LM3S9B81-IQC80-C5 ARM Cortex-M3 MCU, 80 MHz

MPNLM3S9B81-IQC80-C5
Obsolete

Texas Instruments Stellaris ARM Cortex-M3S 9000 series LM3S9B81-IQC80-C5, 32-bit single-core MCU, 80 MHz, 256 KB Flash, 96 KB RAM, Ethernet, CAN, USB OTG, 100-LQFP, -40°C to 85°C.

Texas Instruments LM3S9B81-IQC80-C5 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

LM3S9B81-IQC80-C5 specifications
ParameterValue
SeriesStellaris® ARM® Cortex®-M3S 9000
MountingSurface Mount
Oscillator typeInternal
Program memory typeFLASH
Voltage - supply (Vcc (Vdd))1.235V ~ 1.365V
Operating temperature-40°C~85°C(TA)
Speed80MHz
PackageTray
RAM size96K x 8
Core size32-Bit Single-Core
PeripheralsBrown-out Detect/Reset, DMA, I²S, POR, PWM, WDT
ConnectivityCANbus, EBI/EMI, Ethernet, I²C, IrDA, LINbus, Microwire, SPI, SSI, UART/USART, USB OTG
Number of i (O)65
Core processorARM® Cortex®-M3
Case100-LQFP
Data convertersA/D 16x10b
Program memory size256KB (256K x 8)

Product details

256 KB Flash and 96 KB RAM — firmware and data budget

The 256 KB Flash holds a moderate firmware image — enough for a TCP/IP stack, CANopen or Modbus application layer, and a bootloader. The 96 KB RAM supports multiple packet buffers and a real-time data log without external memory. Designs that need more heap or a larger frame buffer will hit the ceiling; this part is sized for a self-contained control node, not a data logger.

Texas Instruments has marked the LM3S9B81-IQC80-C5 as obsolete. No official successor is listed. For BOM lines requiring this exact MCU, the only supply path is through independent distribution.

The 100-LQFP (14x14 mm) is a standard footprint.

Frequently asked questions

What is the closest pin-compatible alternative to LM3S9B81-IQC80-C5?

No official pin-compatible replacement is listed in the available documentation. Other Stellaris 100-pin Cortex-M3 variants exist in the family, but pin compatibility and memory sizing must be verified against your specific firmware and PCB layout.

What is LM3S9B81-IQC80-C5's listed speed?

The core runs at 80 MHz, which is the maximum clock speed for this Cortex-M3 device.

Where can I buy LM3S9B81-IQC80-C5?

We source and quote this obsolete part to order against an RFQ through independent distribution. Availability and current pricing are confirmed at quote time.