Texas Instruments LM3S8970-IBZ50-A2

Overview

LM3S8970-IBZ50-A2 from Texas Instruments is a 32-bit ARM Cortex-M3 microcontroller with 256 KB flash, 64 KB SRAM, integrated CAN 2.0B controller, 10/100 Ethernet MAC, and hibernation module for ultra-low-power operation. It operates at 50 MHz, supports 3.3 V supply, and targets industrial control and networked sensor nodes requiring deterministic real-time response.

For engineers reviewing the LM3S8970-IBZ50-A2 datasheet, LM3S8970-IBZ50-A2 pinout, LM3S8970-IBZ50-A2 application, or LM3S8970-IBZ50-A2 equivalent, key selection criteria include its integrated Ethernet MAC (no external PHY required), dual CAN channels, hibernation current of 1.7 µA, and support for Thumb-2 instruction set with NVIC-based interrupt handling.

Technical Context

The LM3S8970-IBZ50-A2 implements the ARM Cortex-M3 core with Harvard bus architecture, nested vectored interrupt controller (NVIC), and memory protection unit (MPU). It integrates a dedicated hibernation module with battery-backed RTC and 2 KB SRAM, enabling wake-up from deep sleep in under 1.5 µs.

Peripherals include one 10/100 Ethernet MAC (MII/RMII interface), two CAN 2.0B controllers, four UARTs, two SSI modules, two I²C interfaces, eight PWM outputs, and six general-purpose timers - all clocked from a configurable PLL-driven system clock up to 50 MHz.

Key Specifications

Pinout & Package

LM3S8970-IBZ50-A2 is housed in a 100-pin LQFP (14 mm × 14 mm, 0.5 mm pitch) package with exposed thermal pad. Pin functions are defined per TI SPMS175I datasheet Rev I, including dedicated JTAG/SWD debug pins, dual CAN TX/RX pairs, MII/RMII signal groups, and GPIOs multiplexed with peripheral functions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3S8970-IBZ50-A2, LM3S9B92-IQC50-A2 trades Ethernet for USB and larger memory, while TM4C123GH6PM offers higher clock speed and FPU but requires PCB redesign - making LM3S8970-IBZ50-A2 optimal for legacy industrial nodes where Ethernet + dual CAN + ultra-low-power hibernation are non-negotiable.

Availability

LM3S8970-IBZ50-A2 is available at Aetrix Electronics and suitable for industrial PLC nodes, smart grid sensor hubs, building automation gateways, and remote monitoring terminals requiring stable component supply across extended product lifecycles.

Supply support for LM3S8970-IBZ50-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 company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The Stellaris LM3S series was designed specifically for cost-sensitive, real-time industrial control applications requiring integrated communication peripherals (CAN, Ethernet), deterministic low-latency interrupt response, and ultra-low-power hibernation - before the Tiva C series succeeded it.

FAQ

Does LM3S8970-IBZ50-A2 include an integrated Ethernet PHY?

No, the LM3S8970-IBZ50-A2 contains only the Ethernet MAC layer. An external PHY chip (e.g., DP83848 or LAN8720) is required for physical-layer signaling. The device supports both MII and RMII interfaces, allowing flexible PHY selection based on board space and cost constraints. This separation enables design reuse across different PHY vendors and speeds while maintaining consistent MAC firmware.

What is the hibernation current specification for LM3S8970-IBZ50-A2?

The LM3S8970-IBZ50-A2 achieves 1.7 µA typical hibernation current with the real-time clock running and 2 KB of SRAM retained. This value is measured at 3.3 V and 25°C per TI SPMS175I datasheet Section 6.3.6. Battery backup must be connected to the VBAT pin, and the hibernation module must be configured to retain RTC and memory - critical for battery-operated remote sensors needing multi-year operation.

How many CAN controllers does LM3S8970-IBZ50-A2 support?

The LM3S8970-IBZ50-A2 integrates two independent CAN 2.0B controllers (CAN0 and CAN1), each supporting up to 32 message objects, programmable bit timing, and hardware acceptance filtering. Both controllers operate concurrently and can be assigned to separate CAN buses - essential for applications like vehicle diagnostics (OBD-II on CAN0) and body control (CAN1) or industrial daisy-chain topologies.

Is LM3S8970-IBZ50-A2 pin-compatible with other Stellaris LM3S devices?

No, LM3S8970-IBZ50-A2 is not pin-compatible with most other LM3S devices due to its unique 100-pin LQFP package and specific peripheral pin mapping - especially for Ethernet MII signals and dual CAN transceiver interfaces. While some smaller LM3S variants share GPIO pinouts, the LM3S8970's expanded peripheral set necessitates dedicated routing. Always verify against TI SPMS175I pin diagram before migration.

What debug interface does LM3S8970-IBZ50-A2 support?

The LM3S8970-IBZ50-A2 supports both JTAG and Serial Wire Debug (SWD) interfaces via dedicated pins (TCK, TMS, TDI, TDO, nTRST, SWDIO, SWCLK). SWD mode uses only two pins and is preferred for production programming and debugging. TI's Stellaris ICDI and third-party tools like Segger J-Link fully support this device, enabling real-time trace via the TPIU when enabled in the debug configuration.