The Texas Instruments LM3S6420-IQC25-A2T is a 32-bit ARM Cortex-M3 MCU from the Stellaris® 6000 series, clocked at 25 MHz with 96 KB of Flash program memory and 32 KB of RAM. It integrates Ethernet MAC+PHY alongside IrDA, Microwire, SPI, SSI, and UART/USART serial interfaces — enough connectivity to serve as a networked control node in industrial automation, building management, or telecom equipment without an external network coprocessor. The 46 general-purpose I/O lines and on-chip peripherals (brown-out detect, POR, PWM, watchdog timer) cover the typical sensor-actuator interface needs of a mid-complexity embedded controller.
25 MHz core — what it means for the control loop
At 25 MHz the Cortex-M3 executes single-cycle multiply and hardware divide, so a PID loop or Modbus packet handler finishes in deterministic time. This is not a high-throughput DSP core; it is sized for event-driven control where the Ethernet port carries occasional configuration frames or status reports, not streaming data. The 96 KB Flash holds a moderate firmware image with a TCP/IP stack and application logic; the 32 KB RAM leaves room for a few hundred bytes of packet buffer and local variables.
Industrial temperature range
Rated from -40°C to 85°C, this MCU is specified for factory-floor enclosures, outdoor telecom cabinets, and engine-bay-adjacent electronics where the ambient temperature can swing well beyond commercial limits. The 100-LQFP package (14x14 mm) is a common footprint for rework and inspection.
Lifecycle: obsolete — sourcing reality
The LM3S6420-IQC25-A2T is obsolete per the manufacturer. No direct pin-compatible replacement from TI's current Stellaris or Tiva-C portfolio is listed in the evidence.