Texas Instruments LM3S6537-IBZ50-A2

Overview

LM3S6537-IBZ50-A2 from Texas Instruments is a 32-bit ARM Cortex-M3 microcontroller with 256 KB flash, 64 KB SRAM, integrated Ethernet MAC, dual UARTs, I²C, SSI, ADC (12-bit, 8-channel), 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 networked industrial controllers requiring deterministic real-time response and low-power hibernation.

For engineers reviewing the LM3S6537-IBZ50-A2 datasheet, LM3S6537-IBZ50-A2 pinout, LM3S6537-IBZ50-A2 application, or LM3S6537-IBZ50-A2 equivalent, key selection criteria include Ethernet MAC integration, hibernation current (≤1.9 µA), 50 MHz CPU clock, 100-pin LQFP mechanical compatibility, and StellarisWare® software support for rapid firmware development.

Technical Context

The LM3S6537-IBZ50-A2 implements the ARM Cortex-M3 core with NVIC, SysTick, and MPU, enabling deterministic interrupt latency and memory protection. Its integrated 10/100 Ethernet MAC supports MII interface and IEEE 802.3 compliance without external PHY control logic.

It features a dedicated hibernation module with battery-backed RTC, 2 KB hibernate RAM, and wake-up on RTC match or external GPIO. Analog subsystem includes a 12-bit, 1-MSPS ADC with four independent sample sequencers and internal temperature sensor.

Key Specifications

Pinout & Package

Package: 100-pin LQFP (14 mm × 14 mm, 0.5 mm pitch), RoHS-compliant, moisture sensitivity level 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3S6537-IBZ50-A2, LM3S6965-IBZ50-A2 adds USB but sacrifices hibernation efficiency, while TM4C123GH6PM delivers higher clock speed and more ADC channels but mandates software requalification and lacks identical hibernation module behavior.

Availability

LM3S6537-IBZ50-A2 is available at Aetrix Electronics and suitable for industrial gateways, remote sensor nodes, PLC I/O modules, and smart building controllers requiring stable component supply and long-term obsolescence management.

Supply support for LM3S6537-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 across industrial, automotive, and communications markets.

The Stellaris LM3S family was designed specifically for cost-sensitive, real-time industrial control applications requiring integrated connectivity, deterministic timing, and low-power hibernation-prioritizing Ethernet-ready MCU functionality before the TM4C series.

FAQ

What is the maximum operating frequency of the LM3S6537-IBZ50-A2?

The LM3S6537-IBZ50-A2 operates at a maximum CPU clock frequency of 50 MHz, as specified in the production data sheet (DS-LM3S6537-15852.2743). This frequency is achieved using the internal PLL with an external 6 MHz crystal, and it defines the upper bound for instruction execution, peripheral timing, and real-time control loop performance. The LM3S6537-IBZ50-A2 maintains this speed across its full industrial temperature range (–40°C to +85°C).

Does the LM3S6537-IBZ50-A2 include an integrated Ethernet PHY?

No, the LM3S6537-IBZ50-A2 integrates only the Ethernet MAC layer-not the physical layer (PHY). It supports both MII and RMII interfaces to connect externally to standard 10/100 PHY ICs such as the DP83848 or LAN8720. The LM3S6537-IBZ50-A2 provides all MAC registers, DMA control, and packet buffering, but requires an external PHY for signal-level Ethernet transmission and reception.

What is the hibernation current specification for the LM3S6537-IBZ50-A2?

The LM3S6537-IBZ50-A2 achieves a typical hibernation current of ≤1.9 µA when configured with the internal RTC running from a 32.768 kHz crystal and 2 KB of hibernate RAM retained. This value is measured under production test conditions per the official Texas Instruments datasheet (SPMS131I, July 2014). The LM3S6537-IBZ50-A2 uses dedicated hibernation power gating to isolate non-essential circuitry while preserving RTC and RAM state.

How many ADC channels does the LM3S6537-IBZ50-A2 support, and what is their resolution?

The LM3S6537-IBZ50-A2 includes a single 12-bit successive approximation register (SAR) ADC with up to 8 external input channels (AIN0–AIN7) and one internal temperature sensor channel. It supports simultaneous sampling via four independent 8-step sequencers, enabling flexible trigger sources and hardware averaging. The LM3S6537-IBZ50-A2 ADC achieves 1 MSPS aggregate sampling rate with configurable sample-and-hold timing.

Is the LM3S6537-IBZ50-A2 pin-compatible with other Stellaris LM3S devices?

The LM3S6537-IBZ50-A2 is pin-compatible with other 100-pin LQFP Stellaris MCUs in the LM3S6xxx series, including LM3S6965-IBZ50-A2 and LM3S6100-IBZ50-A2, sharing identical mechanical footprint and core peripheral pin assignments (e.g., UART, SSI, I²C, GPIO). However, differences exist in peripheral enablement and register mapping-so while PCB layout may be reused, firmware must be validated per device. The LM3S6537-IBZ50-A2 does not share pinout with TM4C123x devices despite similar packaging.