Texas Instruments LM3S8938-IQC50-A2

Overview

LM3S8938-IQC50-A2 from Texas Instruments is a 32-bit ARM Cortex-M3 microcontroller with 256 KB flash, 64 KB SRAM, integrated CAN, USB, Ethernet MAC, ADC (10-bit, 1 MSPS), and hibernation module. It operates at 50 MHz and supports industrial temperature range (–40°C to +85°C) in a 100-pin LQFP package. Used in motor control, industrial automation, and embedded networking systems.

For engineers reviewing the LM3S8938-IQC50-A2 datasheet, LM3S8938-IQC50-A2 pinout, LM3S8938-IQC50-A2 application, or LM3S8938-IQC50-A2 equivalent, key selection criteria include its dual CAN interfaces, hibernation-enabled low-power operation, Ethernet MAC without PHY, and integrated analog peripherals for sensor interfacing and closed-loop control.

Technical Context

The LM3S8938-IQC50-A2 implements the ARM Cortex-M3 core with NVIC, SysTick, and MPU, supporting Thumb-2 instruction set and deterministic interrupt latency down to 12 cycles. It integrates a hibernation module with RTC, battery-backed memory, and wake-on-external-event capability.

Peripherals include two CAN 2.0B controllers, one 10/100 Ethernet MAC (no PHY), four UARTs (one with IrDA/SIR), two SSI, two I²C, eight PWM outputs, and a 12-channel 10-bit ADC with hardware averaging and temperature sensor - all clocked from a configurable PLL-based system clock up to 50 MHz.

Key Specifications

Pinout & Package

LM3S8938-IQC50-A2 is housed in a 100-pin LQFP package with exposed thermal pad. Pin functions are multiplexed across GPIO banks A–G, supporting flexible peripheral mapping and signal routing.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3S8938-IQC50-A2, LM3S9B92-IQC50-A2 trades Ethernet for integrated USB PHY - reducing external component count where USB dominates. TM4C123GH6PM delivers higher clock speed and CAN FD, but demands revised PCB layout and driver migration due to architectural enhancements.

Availability

LM3S8938-IQC50-A2 is available at Aetrix Electronics and suitable for industrial motor control, building automation gateways, and smart grid sensor nodes requiring stable component supply and long-term obsolescence planning.

Supply support for LM3S8938-IQC50-A2 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 experience in industrial and automotive microcontrollers.

The Stellaris LM3S series was designed specifically for cost-sensitive, real-time embedded applications demanding integrated connectivity (CAN, USB, Ethernet), low-power operation, and deterministic interrupt response - targeting industrial control and networked sensors.

FAQ

What is the maximum operating frequency of the LM3S8938-IQC50-A2?

The LM3S8938-IQC50-A2 operates at a maximum system clock frequency of 50 MHz, achieved via an internal PLL that multiplies the crystal or external clock input. This frequency is specified under industrial temperature conditions (–40°C to +85°C) and ensures deterministic timing for real-time control loops and communication stacks. The LM3S8938-IQC50-A2 maintains full peripheral functionality-including dual CAN, Ethernet MAC, and ADC-at this rated speed.

Does the LM3S8938-IQC50-A2 include an integrated Ethernet PHY?

No, the LM3S8938-IQC50-A2 integrates only the Ethernet MAC layer compliant with IEEE 802.3, requiring an external PHY (e.g., TI DP83848 or Microchip LAN8720) for physical layer signaling. This architecture allows design flexibility in selecting PHY features such as energy-efficient Ethernet or industrial isolation. The LM3S8938-IQC50-A2 provides MII interface signals and timing control registers to manage the external PHY handshake and data flow.

How does the hibernation module in the LM3S8938-IQC50-A2 reduce power consumption?

The hibernation module in the LM3S8938-IQC50-A2 cuts active current to less than 1 µA by gating clocks to all subsystems except the RTC and battery-backed memory. It retains register state and SRAM contents using a dedicated VBAT rail, enabling wake-up on RTC match, external GPIO event, or HIB interrupt. This capability makes the LM3S8938-IQC50-A2 suitable for battery-operated sensor nodes where multi-year operation is required without compromising data retention or timing accuracy.

Can the LM3S8938-IQC50-A2 support USB device and host modes simultaneously?

Yes, the LM3S8938-IQC50-A2 includes a USB On-The-Go (OTG) controller capable of dynamic role switching between device and host modes, controlled via the USB0ID pin and internal session request logic. It supports full-speed (12 Mbps) operation with integrated transceivers, eliminating the need for external USB PHY components. The LM3S8938-IQC50-A2 firmware can enumerate as a CDC ACM device or act as a host for HID peripherals - all managed through the StellarisWare USB library.

What development tools are officially supported for the LM3S8938-IQC50-A2?

Texas Instruments officially supports the LM3S8938-IQC50-A2 with Keil MDK-ARM, IAR Embedded Workbench, and TI's Code Composer Studio v5.x and earlier. StellarisWare Peripheral Driver Library and evaluation boards like the EK-LM3S8962 provide tested HAL drivers, example projects, and debug infrastructure. The LM3S8938-IQC50-A2 is JTAG-debuggable using standard ARM-compliant tools (e.g., Segger J-Link, TI XDS100v3), with full NVIC and memory map visibility in all supported IDEs.