Texas Instruments LM3S5732-IQR50-A0

Overview

LM3S5732-IQR50-A0 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, and hibernation module. It operates at 50 MHz and supports industrial temperature range (–40°C to +105°C) in a 100-pin LQFP package. Used in motor control, sensor hubs, and programmable logic controllers.

For engineers reviewing the LM3S5732-IQR50-A0 datasheet, LM3S5732-IQR50-A0 pinout, LM3S5732-IQR50-A0 application, or LM3S5732-IQR50-A0 equivalent, key selection criteria include its hibernation-capable real-time clock, μDMA controller for peripheral offload, and integrated analog front-end for direct sensor interfacing without external signal conditioning.

Technical Context

The LM3S5732-IQR50-A0 implements the ARMv7-M architecture with NVIC supporting up to 68 interrupt lines, SysTick timer, and Memory Protection Unit (MPU). Its system-level design integrates a hibernation module with battery-backed RTC and 2 KB of hibernate memory, enabling sub-1 µA deep-sleep operation.

Peripherals include a 12-bit ADC with four sample sequencers and hardware averaging, two UARTs with IrDA/SIR support, one SSI port, and one I²C master/slave interface. Clocking is managed via internal precision oscillator (±1% over temperature), PLL, and multiple gated clock domains.

Key Specifications

Pinout & Package

LM3S5732-IQR50-A0 is housed in a 100-pin LQFP (Low-Profile Quad Flat Package) with exposed thermal pad, JEDEC MS-026AC compliant. Pinout validated per TI SPMS090H datasheet Rev H (July 2014), Table 4-1 "Signal Descriptions" and Figure 1-3 "High-Level Block Diagram".

Key Features

Applications

Equivalent & Alternatives

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

Compared with LM3S5742-IQR50-A0 and TM4C123GH6PM, the LM3S5732-IQR50-A0 delivers optimal cost/performance for UART/SSI-based industrial control where CAN or USB are unnecessary, while maintaining full software compatibility with legacy StellarisWare drivers and tools.

Availability

LM3S5732-IQR50-A0 is available at Aetrix Electronics and suitable for motor control systems, sensor data aggregators, programmable logic controllers, and energy harvesting nodes requiring stable component supply and long-term industrial availability.

Supply support for LM3S5732-IQR50-A0 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, specializing in analog, embedded processing, and wireless technologies with over 90 years of innovation in industrial and automotive electronics.

The Stellaris LM3S series was designed specifically for cost-sensitive, real-time industrial control applications requiring robust analog integration, low-power hibernation, and deterministic interrupt response - targeting factory automation, building control, and motor drive markets.

FAQ

What is the maximum operating frequency of the LM3S5732-IQR50-A0?

The LM3S5732-IQR50-A0 operates at a maximum system clock frequency of 50 MHz, achieved using its internal PLL with an external crystal or internal precision oscillator. This frequency is fully supported across the entire industrial temperature range (–40°C to +105°C) and enables real-time execution of control loops with sub-microsecond latency. The LM3S5732-IQR50-A0 maintains timing compliance per TI SPMS090H datasheet Section 5.2.5.

Does the LM3S5732-IQR50-A0 support in-system programming via UART?

Yes, the LM3S5732-IQR50-A0 includes a factory-programmed ROM bootloader that supports UART-based in-application programming (IAP). This allows firmware updates without JTAG hardware, using only a standard RS-232 or TTL-level UART connection. The LM3S5732-IQR50-A0 bootloader is documented in TI Application Report SPMA075 and requires no external memory or custom loader code.

What is the purpose of the hibernate module in the LM3S5732-IQR50-A0?

The hibernate module in the LM3S5732-IQR50-A0 provides ultra-low-power operation with battery-backed real-time clock (RTC), 2 KB of hibernate RAM, and wake-on-alarm capability. It enables current draw below 1 µA while retaining timekeeping and critical state data - essential for battery-powered remote sensors and energy harvesting systems. The LM3S5732-IQR50-A0 hibernate module is detailed in Section 6 of the SPMS090H datasheet.

How many analog input channels does the LM3S5732-IQR50-A0 ADC support?

The LM3S5732-IQR50-A0 features a single 12-bit SAR ADC with eight analog input channels (AIN0–AIN7), organized into four independent sample sequencers. Each sequencer can be triggered by software, timer, or peripheral events, enabling flexible multi-channel acquisition. The LM3S5732-IQR50-A0 ADC also includes an internal temperature sensor and supports differential input mode for noise rejection.

Is the LM3S5732-IQR50-A0 pin-compatible with other Stellaris LM3S devices?

No, the LM3S5732-IQR50-A0 is not universally pin-compatible across the LM3S family. While it shares the 100-pin LQFP package with several variants (e.g., LM3S5742), pin functions differ - particularly for CAN, additional UARTs, or GPIO mappings. Direct substitution requires verification against each device's specific signal mapping table in the respective datasheet. The LM3S5732-IQR50-A0 pinout is defined in Table 4-1 of SPMS090H.