Texas Instruments LM3S5732-IQR50-A0T

Overview

LM3S5732-IQR50-A0T from Texas Instruments is a 32-bit ARM Cortex-M3 microcontroller with 256 KB flash, 64 KB SRAM, integrated ADC (12-bit, 1 MSPS), dual UARTs, SSI, I²C, PWM, and hibernation module. It operates at 50 MHz and supports industrial temperature range (–40°C to +85°C) in a 64-pin LQFP package. It serves as main system controller in motor control, sensor interface, and embedded HMI applications.

For engineers reviewing the LM3S5732-IQR50-A0T datasheet, LM3S5732-IQR50-A0T pinout, LM3S5732-IQR50-A0T application, or LM3S5732-IQR50-A0T equivalent, key selection criteria include its 50 MHz Cortex-M3 core, hibernation-enabled low-power operation, on-chip analog peripherals, and QFP-64 mechanical compatibility for space-constrained industrial designs.

Technical Context

The LM3S5732-IQR50-A0T implements the ARMv7-M architecture with NVIC, SysTick, and MPU for deterministic real-time execution. Its memory subsystem includes 256 KB of single-cycle flash with prefetch buffer and 64 KB of SRAM with parity protection.

Peripherals are organized into clock-gated modules: two UARTs with IrDA/SIR support, one SSI supporting Motorola/Freescale SPI modes, one I²C master/slave, eight PWM generator blocks, and a 12-channel 12-bit ADC with hardware averaging and temperature sensor. The hibernation module provides RTC, battery-backed memory, and wake-on-RTC/external-pin capability.

Key Specifications

Pinout & Package

LM3S5732-IQR50-A0T is housed in a 64-pin LQFP (Leadless Quad Flat Package) with exposed thermal pad, JEDEC MS-026AC compliant, 10 mm × 10 mm body, 0.5 mm lead pitch, and RoHS-compliant matte tin lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM4F120H5QR and TM4C123GH6PM, the LM3S5732-IQR50-A0T offers proven industrial reliability and lower power in hibernation mode but lacks FPU and USB/Ethernet - making it optimal for cost-sensitive, low-compute, battery-aware embedded controllers where legacy software compatibility is critical.

Availability

LM3S5732-IQR50-A0T is available at Aetrix Electronics and suitable for industrial motor control, sensor data acquisition, embedded HMI, and PLC I/O modules requiring stable component supply and long-lifecycle support.

Supply support for LM3S5732-IQR50-A0T 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, embedded processing, and connectivity solutions across industrial, automotive, and consumer markets.

The Stellaris LM3S series was designed as the first ARM Cortex-M3-based microcontroller family for industrial and embedded applications, emphasizing real-time determinism, low-power hibernation, and integrated analog/motor control peripherals.

FAQ

What is the maximum operating frequency of the LM3S5732-IQR50-A0T?

The LM3S5732-IQR50-A0T operates at a maximum system clock frequency of 50 MHz. This is achieved using the internal PLL with an external crystal (typically 6 MHz) or external clock source. The Cortex-M3 core executes instructions at this frequency, and all peripheral clocks derive from it via configurable dividers. Performance benchmarks confirm consistent 50 MHz operation across the full –40°C to +85°C temperature range specified for the LM3S5732-IQR50-A0T.

Does the LM3S5732-IQR50-A0T support hardware floating-point operations?

No, the LM3S5732-IQR50-A0T does not include a hardware floating-point unit (FPU). It uses the ARM Cortex-M3 core, which implements only integer and fixed-point arithmetic in hardware. Floating-point calculations must be performed in software using the standard C library or optimized CMSIS-DSP routines. For applications requiring hardware FPU, consider the successor LM4F120H5QR, which integrates the Cortex-M4F core and is pin-compatible with the LM3S5732-IQR50-A0T.

What is the purpose of the hibernation module in the LM3S5732-IQR50-A0T?

The hibernation module in the LM3S5732-IQR50-A0T enables ultra-low-power sleep states with retained functionality: it maintains a real-time clock (RTC), preserves up to 2 KB of SRAM using a backup battery, and supports wake events from RTC match or external GPIO assertion. This allows the LM3S5732-IQR50-A0T to achieve sub-2 µA standby current while keeping accurate time and state - critical for battery-powered sensors and energy-harvesting devices where continuous operation is not required.

Can the LM3S5732-IQR50-A0T be programmed in-circuit via JTAG?

Yes, the LM3S5732-IQR50-A0T supports in-circuit programming and debugging via a 4-wire JTAG interface (TCK, TMS, TDI, TDO) and optional SWD (Serial Wire Debug) using compatible tools such as TI's ICDI-based debug probes or third-party J-Link adapters. The JTAG TAP controller is fully IEEE 1149.1 compliant, enabling boundary-scan testing, flash programming, and real-time debugging without requiring external programming hardware beyond a standard debug header.

Is the LM3S5732-IQR50-A0T still in active production by Texas Instruments?

Texas Instruments has discontinued the LM3S series and transitioned to the TM4C family. However, the LM3S5732-IQR50-A0T remains available through authorized distributors and Aetrix Electronics' extended lifecycle program, with guaranteed supply for existing designs. TI's official product change notification (PCN) confirms last-time-buy status, but Aetrix maintains inventory and offers obsolescence mitigation support including cross-reference guidance and migration paths to TM4C123x devices.