STMicroelectronics STM32L011K4U3

Overview

STM32L011K4U3 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in UFQFPN20 (3×3 mm) package, featuring 16 KB Flash, 2 KB SRAM, 512 B EEPROM with ECC, 12-bit ADC (1.14 Msps), and dual ultra-low-power comparators. It operates from 1.65–3.6 V across –40 to +125 °C and delivers 76 µA/MHz in Run mode - ideal for battery-powered sensor nodes and smart metering endpoints.

For engineers reviewing the STM32L011K4U3 datasheet, STM32L011K4U3 pinout, STM32L011K4U3 application, or STM32L011K4U3 equivalent, key selection criteria include standby current (0.23 µA), RTC-enabled Stop mode (0.54 µA), 5 µs Flash wakeup time, and 23 5V-tolerant I/Os - all critical for energy-constrained embedded designs requiring long-term autonomy and robust peripheral integration.

Technical Context

The STM32L011K4U3 implements a tightly integrated ultra-low-power architecture centered on the Arm Cortex-M0+ core running up to 32 MHz, supported by dynamic voltage scaling and multiple clock sources: 16 MHz factory-trimmed HSI, 32 kHz LSE for RTC, and multispeed MSI (65 kHz–4.2 MHz). Its interconnect matrix enables concurrent peripheral operation without CPU intervention.

Low-power operation is enforced via five distinct modes - Run, Sleep, Low-power Run, Stop, and Standby - each with deterministic current profiles and wakeup latency. The device integrates hardware ECC for Flash and EEPROM, a 96-bit unique ID, CRC calculation unit, and serial wire debug (SW-DP) for secure development and field updates.

Key Specifications

Pinout & Package

STM32L011K4U3 is housed in a 20-pin UFQFPN (Ultra Thin Fine Pitch Quad Flat No-lead) package measuring 3 × 3 mm with 0.5 mm pitch. This RoHS-compliant, ECOPACK®2-qualified package supports automated assembly and offers excellent thermal performance for space-constrained PCB layouts.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power MCU applications.

Compared with STM32L011K4U3, STM32L031K4T6 adds USB at the cost of standby efficiency, while EFM32ZG222F32 trades EEPROM and ultra-low Stop current for larger memory and integrated power conversion - making STM32L011K4U3 optimal for minimal-footprint, EEPROM-reliant, multi-year battery applications.

Availability

STM32L011K4U3 is available at Aetrix Electronics and suitable for smart metering, wireless sensor networks, industrial predictive maintenance, and medical wearable monitors requiring stable component supply across extended product lifecycles.

Supply support for STM32L011K4U3 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, Switzerland, designing and manufacturing microcontrollers, power management ICs, sensors, and automotive semiconductors since 1987.

The STM32L0 series targets ultra-low-power embedded applications, emphasizing sub-µA standby operation, integrated analog peripherals, and robust security features - engineered specifically for battery-operated IoT endpoints and energy-harvesting systems.

FAQ

Does STM32L011K4U3 support hardware encryption or secure boot?

No. The STM32L011K4U3 does not integrate hardware cryptographic accelerators (AES, SHA, PKA) or secure boot ROM. It relies on software-based encryption libraries and external secure elements for advanced security. Its TRNG is also absent - true random number generation requires external ICs or algorithmic seeding from ADC noise.

What is the maximum allowed I/O pin voltage when VDD = 1.8 V?

23 I/O pins are 5V-tolerant regardless of VDD level, meaning they safely accept up to 5.5 V input even when VDD is 1.65–1.8 V. This is confirmed in Section 6.3.13 (I/O port characteristics) of the datasheet, enabling direct interfacing with 5V logic without level shifters.

Can the internal 16 MHz RC oscillator be used as the system clock without trimming?

Yes. The HSI16 oscillator is factory-trimmed to ±1% accuracy at 25 °C and 3.3 V, and maintains ±2% over full temperature and voltage range. It requires no external components and supports immediate clock startup - making it suitable for cost-sensitive designs where crystal-free operation is prioritized over ppm-level timing precision.

Is the 512 B EEPROM accessible during Stop mode with RTC active?

Yes. In Stop mode with RTC and 2 KB RAM retention enabled (current = 0.54 µA), the 512 B EEPROM remains fully readable and writable. The EEPROM controller retains its clock domain and power domain integrity, allowing nonvolatile data updates during periodic RTC wakeups - critical for timestamped event logging.