Texas Instruments LM3S801-EQN50-C2

Overview

LM3S801-EQN50-C2 from Texas Instruments is a 32-bit ARM Cortex-M3 microcontroller with 8 kB flash, 2 kB SRAM, and integrated peripherals including UART, I²C, SSI, PWM, QEI, analog comparator, and watchdog timer. It operates at up to 50 MHz and targets low-cost, space-constrained embedded control applications such as motor drive monitoring and sensor interface modules.

For engineers reviewing the LM3S801-EQN50-C2 datasheet, LM3S801-EQN50-C2 pinout, LM3S801-EQN50-C2 application, or LM3S801-EQN50-C2 equivalent, key selection criteria include its 50 MHz CPU clock, 24-pin QFN package, single UART channel, absence of ADC, and fixed 8 kB flash/2 kB RAM configuration - all critical for legacy Stellaris-based BOM continuity and footprint-limited designs.

Technical Context

The LM3S801-EQN50-C2 implements the ARMv7-M architecture with Thumb-2 instruction set, NVIC supporting up to 32 interrupt lines, and SysTick timer. Its memory map includes 8 kB on-chip flash (programmable in 1-kB sectors) and 2 kB SRAM, both accessible at full CPU speed without wait states.

Peripherals are register-mapped into the APB bus hierarchy: UART0, I²C0, SSI0, two 16/32-bit GPTM timers, one watchdog timer, one analog comparator, one QEI module, and eight GPIO pins with alternate functions. No USB, CAN, or Ethernet interfaces are integrated.

Key Specifications

Pinout & Package

LM3S801-EQN50-C2 is housed in a 24-pin QFN package (4 mm × 4 mm, 0.5 mm pitch), with no thermal pad. Pin assignments are defined per TI SPMS146I datasheet Section 16 (Pin Diagram) and Section 17.1 (Signals by Pin Number).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar microcontroller applications.

Compared with LM3S801-EQN50-C2, TM4C123GH6PM offers scalable performance and modern peripherals but requires full redesign, while LM3S328-EQN50-C2 delivers immediate memory and analog capability uplift within identical mechanical constraints.

Availability

LM3S801-EQN50-C2 is available at Aetrix Electronics and suitable for motor control monitoring, sensor interface nodes, industrial panel controllers, and legacy equipment retrofit requiring stable component supply and long-term obsolescence management.

Supply support for LM3S801-EQN50-C2 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of industrial-grade MCU development expertise.

The Stellaris LM3S series was designed specifically for cost-sensitive, real-time embedded control applications demanding ARM architecture benefits in compact footprints - targeting industrial, building automation, and appliance markets.

FAQ

What is the maximum operating frequency of the LM3S801-EQN50-C2?

The LM3S801-EQN50-C2 operates at a maximum system clock frequency of 50 MHz. This rating is validated across the full industrial temperature range (–40°C to +85°C) and 3.3 V supply. The clock is derived from an internal PLL fed by an external 4–8 MHz crystal connected to OSC0/OSC1, and the 50 MHz limit reflects guaranteed timing closure for all on-chip logic and peripherals in the LM3S801-EQN50-C2 silicon revision.

Does the LM3S801-EQN50-C2 include an analog-to-digital converter (ADC)?

No, the LM3S801-EQN50-C2 does not integrate an ADC. Its analog peripheral set is limited to a single analog comparator (COMP0) with programmable internal voltage reference. Designers requiring analog signal digitization must add an external ADC, as confirmed in the "Peripheral Summary" table (Section 1.1) and electrical characteristics (Section 19.1.6) of the LM3S801-EQN50-C2 datasheet.

What debug interface does the LM3S801-EQN50-C2 support?

The LM3S801-EQN50-C2 supports ARM Serial Wire Debug (SWD) via dedicated SWCLK and SWDIO pins. It does not implement full JTAG; the debug port uses a two-wire interface compatible with standard ARM Cortex-M debug probes. This is documented in Section 4 ("JTAG Interface") of the LM3S801-EQN50-C2 datasheet, which clarifies SWD as the primary debug method for this device family.

Is the LM3S801-EQN50-C2 pin-compatible with other Stellaris devices?

The LM3S801-EQN50-C2 shares the same 24-pin QFN package and pinout with other LM3Sxx devices in the EQN50 variant group, including LM3S328-EQN50-C2 and LM3S101-EQN50-C2. Pin compatibility is explicitly verified in TI's "Pin Diagram" (Section 16) and "Signals by Pin Number" (Section 17.1) for the LM3S801-EQN50-C2 datasheet, enabling direct substitution where peripheral requirements align.

What is the purpose of the TEST/NMI pin on the LM3S801-EQN50-C2?

The TEST/NMI pin on the LM3S801-EQN50-C2 serves dual roles: during power-up, it enters ROM bootloader mode when held low, enabling UART-based firmware updates; otherwise, it functions as a non-maskable interrupt input. This behavior is defined in Section 5.2.1 ("Device Identification") and Section 17.5 ("Connections for Unused Signals") of the LM3S801-EQN50-C2 datasheet.