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Texas Instruments LM3S9781-IQC80-C5 — Microcontrollers & Processors (MCU / MPU / DSP)

LM3S9781-IQC80-C5 Stellaris ARM Cortex-M3 MCU, 80MHz, 128KB Flash, 100-LQFP

MPNLM3S9781-IQC80-C5
Obsolete

Texas Instruments Stellaris® ARM® Cortex®-M3S 9000 series, LM3S9781-IQC80-C5, 32-bit single-core MCU, 80MHz, 128KB Flash, 64K x 8 SRAM, 65 I/O, CANbus/Ethernet/USB OTG, 100-LQFP (14x14), -40°C to 85°C.

Texas Instruments LM3S9781-IQC80-C5 datasheet (PDF)
Independent supplier — new & surplus stockAuthenticity-screened · ESD-safe packingListing updated Jul 2026

Specifications

LM3S9781-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 size64K 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 size128KB (128K x 8)

Product details

The 80 MHz ARM Cortex-M3 core, combined with the DMA controller and the 64 KB SRAM, can sustain a full Ethernet TCP/IP stack alongside a CANopen master node without dropping frames. That matters for a panel controller that must forward Modbus TCP requests to a dozen drives on a CAN bus — the core has enough headroom to run FreeRTOS or a bare-metal scheduler handling the two protocol stacks without a second MCU.

128 KB Flash — firmware update constraint

128 KB of Flash limits the firmware image after the bootloader and vector table. That is adequate for a fixed-function gateway with a pre-compiled protocol stack.

Frequently asked questions

Is LM3S9781-IQC80-C5 obsolete?

Yes, the LM3S9781-IQC80-C5 is obsolete per TI's lifecycle record. No factory production remains; the part is only available through independent distribution as surplus or new-old-stock inventory.

What is the replacement for LM3S9781-IQC80-C5?

No official replacement part number is listed by TI for the LM3S9781-IQC80-C5. For a pin-compatible drop-in, you would need to evaluate other Stellaris 9000-series devices with the same 100-LQFP footprint and supply voltage, but no direct successor is documented. The independent channel is the only source for this exact order code.

Where to buy LM3S9781-IQC80-C5?

The LM3S9781-IQC80-C5 is sourced to order through independent distribution. Submit an RFQ to confirm current availability and pricing; each lot is quoted individually based on inventory on hand.

What is LM3S9781-IQC80-C5's listed speed?

The core is rated for 80 MHz operation. That is the maximum clock for the ARM Cortex-M3 core on this device.

What is the pinout of LM3S9781-IQC80-C5?

The pinout is defined in the TI datasheet for the 100-LQFP package. The 100 pins include 65 GPIOs multiplexed with the peripheral functions (Ethernet, CAN, USB, UART, SPI, I²C, etc.). Download the official datasheet PDF for the full pin assignment table.