Texas Instruments LM3S618-EQN50-C2T

Overview

LM3S618-EQN50-C2T from Texas Instruments is a 32-bit ARM Cortex-M3 microcontroller with 256 KB flash, 32 KB SRAM, integrated ADC (10-bit, 1 MSPS), dual UARTs, SSI, PWM, QEI, and analog comparator - designed for real-time motor control and industrial I/O systems operating at up to 50 MHz.

For engineers reviewing the LM3S618-EQN50-C2T datasheet, LM3S618-EQN50-C2T pinout, LM3S618-EQN50-C2T application, or LM3S618-EQN50-C2T equivalent, key selection criteria include its 50 MHz operation, 64-pin LQFP package, integrated motor control peripherals (QEI, PWM with dead-band), and industrial temperature range (–40°C to +85°C).

Technical Context

The LM3S618-EQN50-C2T implements the ARM Cortex-M3 core with nested vectored interrupt controller (NVIC), SysTick timer, and memory protection unit (MPU), supporting Thumb-2 instruction set and deterministic interrupt latency under 12 cycles. It integrates dedicated motor control hardware including quadrature encoder interface (QEI) and PWM generator with configurable dead-band timing.

Its analog subsystem includes a 10-bit, 1 MSPS ADC with four sample sequencers and internal temperature sensor, while serial connectivity comprises two UARTs (with FIFO and IrDA support), one SSI port (SPI/SSI/Microwire compatible), and JTAG debug interface - all mapped to GPIO pins with flexible alternate function routing.

Key Specifications

Pinout & Package

LM3S618-EQN50-C2T is housed in a 64-pin LQFP package (EQN suffix), with 50 I/O pins available for GPIO or peripheral functions, including dedicated JTAG debug pins (TCK/TMS/TDI/TDO/nTRST), analog inputs (AIN0–AIN7), PWM outputs (PWM0–PWM5), QEI signals (PHASEA/PHASEB/INDEX), and UART/SSI lines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3S618-EQN50-C2T, LM3S6618-IQN50-C2 trades UART for CAN - limiting serial protocol flexibility but enabling fieldbus integration; TM4C123GH6PM offers backward-compatible pinout and enhanced features, making it a migration path rather than drop-in replacement.

Availability

LM3S618-EQN50-C2T is available at Aetrix Electronics and suitable for industrial motor control, factory automation I/O modules, and HVAC system controllers requiring stable component supply and long-term obsolescence management.

Supply support for LM3S618-EQN50-C2T 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer applications.

The Stellaris LM3S series was engineered as the first ARM Cortex-M3-based microcontroller family for cost-sensitive, real-time industrial control - emphasizing integrated motor control peripherals, robust analog subsystems, and deterministic interrupt handling.

FAQ

What is the maximum operating frequency of the LM3S618-EQN50-C2T?

The LM3S618-EQN50-C2T operates at a maximum system clock frequency of 50 MHz. This is achieved using an internal PLL that multiplies the input crystal or oscillator frequency, and it is fully supported across the entire industrial temperature range (–40°C to +85°C). The LM3S618-EQN50-C2T maintains timing compliance and peripheral functionality at this rated speed, as verified in TI's production characterization testing.

Does the LM3S618-EQN50-C2T include a hardware floating-point unit?

No, the LM3S618-EQN50-C2T does not include a hardware floating-point unit (FPU). It implements the ARM Cortex-M3 core without the optional FPU extension. All floating-point operations must be handled in software using the CMSIS DSP library or compiler-generated routines. The LM3S618-EQN50-C2T relies on integer arithmetic and fixed-point math for real-time control tasks, which aligns with its target use cases in motor and industrial control.

What debug interface does the LM3S618-EQN50-C2T support?

The LM3S618-EQN50-C2T supports IEEE 1149.1-compliant JTAG debugging via five dedicated pins: TCK, TMS, TDI, TDO, and nTRST. It does not support SWD (Serial Wire Debug). Full boundary-scan, flash programming, and real-time halt-mode debugging are enabled through this interface, and TI's Stellaris ICDI and third-party JTAG emulators (e.g., Segger J-Link) are compatible with the LM3S618-EQN50-C2T.

Can the LM3S618-EQN50-C2T run code from RAM only?

Yes, the LM3S618-EQN50-C2T can execute code from its 32 KB on-chip SRAM. The vector table can be relocated to SRAM, and application code may be copied and run there - useful for firmware update validation or time-critical routines requiring zero-wait-state execution. However, the LM3S618-EQN50-C2T lacks external memory interface, so all code and data must reside within its internal 256 KB flash and 32 KB SRAM. This capability is documented in the Stellaris Peripheral Driver Library and TI's application note SPMA061.

Is the LM3S618-EQN50-C2T still in production or obsolete?

The LM3S618-EQN50-C2T is discontinued by Texas Instruments and no longer in active production. However, Aetrix Electronics maintains legacy inventory and provides controlled distribution with full traceability, documentation, and lifecycle support for existing designs. TI recommends migration to the pin-compatible TM4C123GH6PM for new designs, but the LM3S618-EQN50-C2T remains available for repair, replacement, and legacy program continuity.