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STMicroelectronics STM32L431KBU6
- Part No.:
- STM32L431KBU6
- Manufacturer:
- STMicroelectronics
- Category:
- Microcontrollers
- Package:
- 32-UFQFN Exposed Pad
- Datasheet:
-
STM32L431KBU6.pdf
- Description:
- IC MCU 32BIT 128KB FLSH 32UFQFPN
- Quantity:
- Payment:
- Shipping:
Inventory:2,599
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Product details
Overview
STM32L431KBU6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 256 KB Flash, 64 KB SRAM, and integrated analog peripherals including 12-bit ADC (5 Msps), dual 12-bit DACs, op-amp with PGA, and two ultra-low-power comparators. It targets battery-powered IoT sensors, portable medical devices, and smart metering systems requiring sub-µA standby operation and robust mixed-signal capability.
For engineers reviewing the STM32L431KBU6 datasheet, STM32L431KBU6 pinout, STM32L431KBU6 application, or STM32L431KBU6 equivalent, key selection criteria include its 8 nA shutdown current, 4 µs wake-up from Stop mode, FlexPowerControl architecture, and support for CAN 2.0B, SAI audio interface, and capacitive touch sensing across 21 channels.
Technical Context
The STM32L431KBU6 integrates an Adaptive Real-time Accelerator (ART Accelerator™) enabling zero-wait-state execution from Flash at 80 MHz, alongside a memory protection unit (MPU) and interconnect matrix for deterministic peripheral access. Its power architecture includes five low-power modes-Shutdown (8 nA), Standby (28 nA), Stop 2 (1.0 µA), and Run (84 µA/MHz)-with BOR, VBAT backup domain, and hardware calendar RTC.
Clock system flexibility is provided by dual PLLs (system/audio/ADC), four internal oscillators (HSI16, MSI, LSI, HSI48), and external options (4–48 MHz HSE, 32.768 kHz LSE), all auto-trimmed for accuracy better than ±0.25%. Analog subsystems operate on independent supplies, supporting simultaneous high-speed conversion and low-noise signal conditioning.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core | Arm Cortex-M4 with FPU, 80 MHz max, 100 DMIPS - enables real-time DSP and control algorithms without external co-processor |
| Memory | 256 KB Flash (single-bank, code readout protected), 64 KB SRAM (16 KB with parity) - supports secure firmware storage and error-resilient data buffers |
| Low-power modes | 8 nA Shutdown, 28 nA Standby, 1.0 µA Stop 2 - extends battery life in maintenance-free edge nodes for >10 years |
| Analog peripherals | 1× 12-bit ADC @ 5 Msps (200 µA/Msps), 2× 12-bit DACs, 1× op-amp with PGA, 2× comparators - enables sensor signal chain integration without external analog ICs |
| Communication | 1× SAI, 3× I²C (FM+), 4× USART, 1× LPUART, 3× SPI, 1× QuadSPI, 1× CAN 2.0B - supports audio streaming, multi-sensor I²C buses, and industrial fieldbus connectivity |
| Timers & RTC | 11 timers including advanced motor-control TIM1, 2× low-power LPTIMs (active in Stop), HW calendar RTC with calibration - delivers precise timing for motor control, sleep scheduling, and timestamped logging |
| Package | UFQFPN32 (5 × 5 mm, 0.5 mm pitch) - compact footprint suitable for space-constrained wearables and handheld instruments |
Pinout & Package
STM32L431KBU6 uses the UFQFPN32 package: 32-pin, 5 × 5 mm body, 0.5 mm pitch, exposed thermal pad, RoHS-compliant and ECOPACK2® certified.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VDD, VSS | Core power supply / ground | Dual 1.71–3.6 V supply rails with decoupling requirements per datasheet Section 6.3.6; supports dynamic voltage scaling |
| VDDA, VSSA | Analog power / ground | Independent 1.62–3.6 V analog domain supply - isolates noise-sensitive ADC/DAC/OPAMP from digital switching |
| PA0–PA15, PB0–PB15, PC0–PC15, PD0–PD2 | General-purpose I/O | Up to 83 fast I/Os (most 5 V-tolerant); multiple alternate functions mapped via AF0–AF15 - enables flexible peripheral routing and board layout optimization |
| NRST | Active-low reset input | Internal pull-up; accepts external reset pulse ≥ 20 ns - ensures reliable initialization under brown-out or ESD events |
| BOOT0 | Boot mode selection | High at power-on selects system memory boot (for DFU); tied low for main Flash execution - critical for firmware recovery and production programming |
| VBAT | RTC/backup register supply | Accepts coin-cell or supercap input (1.65–3.6 V); sustains RTC and 32×32-bit registers in Shutdown - enables timekeeping during main power loss |
Key Features
| Feature | Design Value |
|---|---|
| FlexPowerControl architecture | Enables granular power gating per peripheral and voltage scaling (VOS0/VOS1/VOS3), reducing active current to 84 µA/MHz and Stop 2 to 1.0 µA |
| ART Accelerator™ | Eliminates Flash wait states at 80 MHz, delivering 3.42 CoreMark/MHz - improves deterministic latency for real-time control loops |
| Capacitive touch sensing (TSC) | 21-channel controller supporting touchkey, linear, and rotary sensors with hardware charge transfer - replaces mechanical buttons with robust, sealed UI |
| True random number generator (RNG) | NIST SP800-90B compliant entropy source - provides cryptographically secure keys for TLS handshake and firmware signing |
| SAI serial audio interface | Supports I²S, MSB-justified, PCM, and AC'97 protocols with FIFO and DMA - enables direct connection to MEMS microphones or audio codecs without FPGA glue logic |
Applications
| Wearable Health Monitor | Smart Utility Meter |
|---|---|
Use Scenario: Continuous ECG/PPG acquisition with Bluetooth LE telemetry and local anomaly detection. IC Role / Device Role / Timing Role: Central MCU managing analog front-end (ADC + OPAMP + COMP), real-time filtering (Cortex-M4 FPU), and low-power BLE wakeup via LPUART. Use Value: 280 nA Standby with RTC allows monthly sync windows; 5 Msps ADC captures high-fidelity biosignals; TSC enables touchless UI navigation. |
Use Scenario: Electricity/water/gas meter with tamper detection, pulse counting, and NB-IoT backhaul. IC Role / Device Role / Timing Role: System controller handling metrology ADC sampling, magnetic/tamper event capture (EXTI), and CAN-based local bus communication. Use Value: 8 nA Shutdown mode preserves battery during 15-year deployment; CAN 2.0B interfaces with legacy AMI modules; CRC unit validates firmware updates over-the-air. |
| Industrial Wireless Sensor Node | Portable Diagnostic Instrument |
Use Scenario: Battery-powered vibration/temperature/humidity node transmitting LoRaWAN packets every 15 minutes. IC Role / Device Role / Timing Role: Low-power host managing multi-sensor polling (I²C/SPI), data fusion, and scheduled radio wake-up via LPTIM2. Use Value: 4 µs wake-up from Stop mode minimizes idle current; QuadSPI supports external FRAM for cyclic logging; VREFINT enables ratiometric sensor calibration. |
Use Scenario: Handheld ultrasound or point-of-care blood analyzer with analog signal conditioning and display driver. IC Role / Device Role / Timing Role: Mixed-signal processor driving DAC-based transducer excitation, digitizing echo returns (ADC), and rendering waveforms on LCD via FSMC. Use Value: Dual 12-bit DACs generate precise RF burst patterns; op-amp PGA amplifies weak return signals; 176.7 ULPBench® score confirms energy efficiency per computation cycle. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar ultra-low-power Cortex-M4 MCU applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| STM32L432KBU6 | Same core/peripherals but includes USB 2.0 FS device controller; lacks CAN and SAI; 128 KB Flash | Better suited for USB-CDC HID devices (e.g., diagnostic dongles); not viable where CAN fieldbus or audio streaming is required | Select when USB connectivity outweighs CAN/SAI needs and Flash budget permits reduction from 256 KB to 128 KB |
| STM32L476RG | Higher Flash (1 MB), larger SRAM (128 KB), adds Chrom-ART accelerator and TFT-LCD controller; same low-power profile | Targeted at HMI-rich applications (e.g., color display panels); over-spec'd for simple sensor nodes due to cost and pin count | Choose only if display interface or >256 KB code size justifies 64-pin LQFP100 footprint and higher BOM cost |
Compared with STM32L432KBU6, the STM32L431KBU6 provides CAN and SAI at full 256 KB Flash - essential for industrial gateways and audio edge devices; versus STM32L476RG, it offers identical low-power performance in a smaller, lower-cost 32-pin package ideal for minimal-feature deployments.
Availability
STM32L431KBU6 is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, and industrial wireless sensor nodes requiring stable component supply, long-term lifecycle assurance, and ECOPACK2® environmental compliance.
Supply support for STM32L431KBU6 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
STMicroelectronics is a global semiconductor leader headquartered in Geneva, designing and manufacturing microcontrollers, power management ICs, sensors, and analog chips for automotive, industrial, and consumer markets.
The STM32L4 series targets ultra-low-power embedded applications demanding high performance-per-milliwatt, integrating advanced power gating, adaptive clocking, and rich analog/mixed-signal peripherals into scalable Cortex-M4 platforms.
FAQ
What is the maximum operating temperature range for STM32L431KBU6?
The STM32L431KBU6 is qualified for industrial operation from –40 °C to +85 °C. This rating is confirmed in Section 6.3.1 of DS11453 Rev 3 and applies to all package variants including the UFQFPN32. No derating is required within this range for standard voltage scaling (VOS1).
Does STM32L431KBU6 support hardware encryption acceleration?
No - the STM32L431KBU6 does not integrate a dedicated cryptographic accelerator (e.g., AES, PKA, or HASH). It relies on software libraries (STM32CubeL4) for encryption; secure key storage is enabled via proprietary readout protection (RDP Level 2) and 96-bit unique ID.
Can the internal 16 MHz RC oscillator (HSI16) be used as the system clock source?
Yes - HSI16 is factory-trimmed to ±1% accuracy and can serve as the main system clock via the RCC configuration. It supports full 80 MHz operation when used with PLL multiplication, and remains active in Sleep mode for fast wake-up without external crystal startup delay.
How many GPIO pins support external interrupt capability on STM32L431KBU6?
All 32 GPIO pins on the UFQFPN32 package (PA0–PA15, PB0–PB15, PC0–PC15, PD0–PD2) support external interrupt generation via the EXTI line mapping. Each pin maps to one of 23 EXTI lines, with up to 5 pins configurable as wakeup sources from Standby/Shutdown modes.
STM32L431KBU6 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- STMicroelectronics
- Package/Case:
- 32-UFQFN Exposed Pad
- Series:
- STM32L4
- Packaging:
- Tray
- Product Status:
- Active
- Programmable:
- Not Verified
- Core Processor:
- ARM® Cortex®-M4
- Core Size:
- 32-Bit Single-Core
- Speed:
- 80MHz
- Connectivity:
- CANbus, I2C, IrDA, LINbus, QSPI, SAI, SPI, SWPMI, UART/USART
- Peripherals:
- Brown-out Detect/Reset, DMA, PWM, WDT
- Number of I/O:
- 26
- Program Memory Size:
- 128KB (128K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 64K x 8
- Voltage - Supply (Vcc/Vdd):
- 1.71V ~ 3.6V
- Data Converters:
- A/D 10x12b; D/A 2x12b
- Oscillator Type:
- Internal
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
STM32L431KBU6 FAQ
1.How can I place an order for STM32L431KBU6 through Aetrix?
Please submit a Request for Quotation (RFQ) for STM32L431KBU6 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for STM32L431KBU6 reliable?
The price and inventory of STM32L431KBU6 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STM32L431KBU6 is usually 5 days.
3.What payment methods are accepted for STM32L431KBU6?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STM32L431KBU6 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STM32L431KBU6?
STM32L431KBU6 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STM32L431KBU6 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for STM32L431KBU6?
For technical support, including STM32L431KBU6 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STM32L431KBU6 requirements.
6.How does Aetrix verify that STM32L431KBU6 is sourced from the original manufacturer or authorized distributors?
All STM32L431KBU6 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STM32L431KBU6 meets industry standards.
7.What is the process for return or replacement of STM32L431KBU6?
All STM32L431KBU6 units undergo pre-shipment inspection (PSI). If there is an issue with STM32L431KBU6, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The STM32L431KBU6 part is unused and in its original packaging.
Return procedure for STM32L431KBU6:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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