STM32L431CBT6 – STMicroelectronics Ultra-Low-Power Arm Cortex-M4 Microcontroller

Product Overview

The STM32L431CBT6 is an ultra-low-power 32-bit microcontroller (MCU) manufactured by STMicroelectronics. It belongs to the STM32L4 series, designed for applications requiring low energy consumption, high analog performance, advanced connectivity, and real-time embedded processing.

The device is based on an Arm Cortex-M4 32-bit RISC core with Floating Point Unit (FPU), operating at up to 80MHz. It integrates 256KB Flash memory, 64KB SRAM, a high-speed 12-bit ADC, 2-channel DAC, operational amplifier, comparators, capacitive sensing capability, and a wide range of communication peripherals. STMicroelectronics

The STM32L431CBT6 uses a 48-pin LQFP package and is optimized for battery-powered and energy-efficient embedded systems, including industrial sensors, IoT nodes, smart meters, portable devices, and low-power control applications. STMicroelectronics

Part Number Breakdown

Competitive Advantages

✔ Ultra-low-power Arm Cortex-M4 MCU

✔ 80MHz processing performance

✔ Integrated FPU and DSP instructions

✔ 256KB Flash + 64KB SRAM

✔ Advanced analog peripherals:

• 12-bit ADC up to 5Msps
• Dual 12-bit DAC
• Op-Amp
• Comparators

✔ Extensive connectivity:

• USB FS
• CAN
• SPI
• USART/UART
• I²C
• SDMMC

✔ Up to 21-channel capacitive sensing

✔ Quad-SPI external memory interface

✔ Industrial temperature operation

✔ Compact 48-pin LQFP package

✔ Ideal for IoT, smart meters, industrial sensors, portable electronics, and low-power embedded systems

Key Features

1. Arm Cortex-M4 Core with FPU and DSP Support

The STM32L431CBT6 integrates an Arm Cortex-M4 core with:

• Single-precision FPU
• DSP instructions
• Memory Protection Unit (MPU) STMicroelectronics

Benefits:

• Enables efficient floating-point calculations
• Supports digital signal processing algorithms
• Improves performance for sensor fusion applications
• Suitable for motor control, measurement, and embedded AI preprocessing

---

2. Ultra-Low-Power Architecture

The STM32L431 series is designed around ST’s FlexPowerControl low-power architecture. It supports multiple energy-saving modes, including:

• Shutdown mode
• Standby mode
• Stop modes
• Low-power run modes STMicroelectronics

Benefits:

• Extends battery life significantly
• Suitable for always-on IoT devices
• Enables energy-efficient sensor nodes
• Supports portable and wireless applications

---

3. 80MHz High-Efficiency Processing

The MCU operates at up to 80MHz, providing a balance between computing capability and power consumption. STMicroelectronics

Benefits:

• Handles real-time embedded tasks
• Supports RTOS applications
• Suitable for communication stacks
• Provides sufficient performance for sensor-processing workloads

---

4. 256KB Flash Memory

The STM32L431CBT6 integrates 256KB embedded Flash memory. STMicroelectronics

Benefits:

• Stores application firmware internally
• Supports larger embedded software stacks
• Reduces external memory requirements
• Enables secure firmware protection features

---

5. 64KB SRAM with Parity Protection

The device integrates 64KB SRAM, including memory with hardware parity-check capability. STMicroelectronics

Benefits:

• Supports real-time data processing
• Improves memory reliability
• Suitable for industrial applications
• Provides buffer space for communication and sensor data

---

6. High-Performance Analog Peripherals

The STM32L431CBT6 integrates advanced analog resources:

• 12-bit ADC up to 5Msps
• Two 12-bit DAC channels
• One operational amplifier
• Two ultra-low-power comparators STMicroelectronics

Benefits:

• Direct sensor interfacing
• Accurate analog measurement
• Reduces external analog components
• Suitable for instrumentation and control systems

---

7. Advanced Capacitive Touch Sensing

The MCU supports up to 21 capacitive sensing channels. STMicroelectronics

Benefits:

• Enables touch buttons and sliders
• Suitable for consumer interfaces
• Reduces mechanical components
• Supports modern human-machine interaction designs

---

8. Rich Communication Interfaces

The STM32L431CBT6 supports:

• 3 × I²C
• 4 × USART
• 1 × LPUART
• 3 × SPI
• SAI audio interface
• CAN 2.0B
• SDMMC STMicroelectronics

Benefits:

• Supports complex embedded systems
• Connects multiple sensors and modules
• Enables industrial communication
• Suitable for IoT gateways and smart devices

---

9. Quad-SPI External Memory Interface

The device includes a Quad-SPI interface for external Flash memory expansion. STMicroelectronics

Benefits:

• Enables larger firmware storage
• Supports external data memory
• Useful for graphics or data-logging applications
• Improves system scalability

---

10. USB and CAN Connectivity

The MCU provides:

• USB 2.0 Full-Speed interface
• CAN 2.0B communication STMicroelectronics

Benefits:

• Suitable for industrial communication
• Enables USB-connected devices
• Supports automotive and automation networks
• Reduces external communication IC requirements

---

11. Security and Protection Functions

Integrated security features include:

• Read protection
• Write protection
• Proprietary code protection
• Firewall protection
• True random number generator
• CRC unit
• 96-bit unique device ID STMicroelectronics

Benefits:

• Protects firmware intellectual property
• Supports secure IoT designs
• Enables device authentication
• Improves product reliability

Applications

IoT Devices

• Wireless sensor nodes
• Smart home devices
• Environmental monitoring systems
• Connected controllers
• Battery-powered IoT products

---

Industrial Sensors and Control

• Industrial measurement systems
• Factory sensors
• Automation controllers
• Data acquisition equipment
• Embedded monitoring devices

---

Smart Meters

• Electricity meters
• Water meters
• Gas meters
• Energy monitoring devices

---

Portable Electronics

• Wearable devices
• Handheld instruments
• Portable medical equipment
• Battery-powered terminals

---

Motor Control Applications

• Small motor controllers
• Fan controllers
• Pump control systems
• Robotics subsystems

---

Human-Machine Interface

• Capacitive touch panels
• Smart buttons
• Control panels
• Appliance interfaces