STMicroelectronics STM32L071K8U3

Overview

STM32L071K8U3 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in UFQFPN32 (5x5 mm) package, featuring 64 KB Flash, 20 KB SRAM, 6 KB EEPROM with ECC, 12-bit ADC (1.14 Msps), and operating from 1.65 V to 3.6 V across –40 °C to +125 °C. It delivers 0.95 DMIPS/MHz performance and supports battery-powered IoT sensor nodes requiring long-term operation on coin cells.

For engineers reviewing the STM32L071K8U3 datasheet, STM32L071K8U3 pinout, STM32L071K8U3 application, or STM32L071K8U3 equivalent, key selection criteria include standby current (0.29 µA), RTC-enabled Stop mode (0.86 µA), 5 µs Flash wakeup time, and integrated 32 kHz RTC oscillator with calibration - all critical for energy-constrained edge sensing and wireless telemetry designs.

Technical Context

The STM32L071K8U3 implements a single-core Arm Cortex-M0+ with Memory Protection Unit (MPU), running at up to 32 MHz using multiple clock sources: factory-trimmed 16 MHz HSI (±1%), 32 kHz LSE for RTC, and programmable MSI (65 kHz–4.2 MHz). Its power architecture includes three low-power modes (Stop, Standby, Low-power Run) with dedicated voltage regulators and brownout reset (BOR) with five threshold levels.

Analog subsystem integration includes two ultra-low-power comparators (operable down to 1.65 V), a temperature sensor, internal voltage reference (VREFINT), and a 12-bit ADC supporting up to 16 channels with hardware oversampling. Peripheral interconnect uses a multi-layer AHB/APB matrix enabling concurrent DMA transfers across ADC, USART, SPI, I2C, and timers without CPU intervention.

Key Specifications

Pinout & Package

STM32L071K8U3 is housed in a 32-pin UFQFPN (5 × 5 mm, 0.5 mm pitch) package compliant with ECOPACK2 environmental standards. The compact footprint supports high-density PCB layouts in space-constrained wearables and smart meters.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L072K8U3, this part omits cryptographic accelerators but retains identical power profiles and analog capability - ideal for trusted environments without data-at-rest encryption needs. Versus STM32L031K6U3, it provides double Flash, full EEPROM, and enhanced timer resources essential for complex scheduling and data persistence.

Availability

STM32L071K8U3 is available at Aetrix Electronics and suitable for smart utility metering, wireless sensor nodes, automotive cabin control, and medical wearables requiring stable component supply across extended product lifecycles.

Supply support for STM32L071K8U3 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, and MEMS sensors for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications demanding sub-µA standby, integrated EEPROM, and extended temperature operation - optimized for battery-operated IoT endpoints and energy-harvesting systems.

FAQ

What is the maximum operating frequency of the STM32L071K8U3?

The STM32L071K8U3 operates at up to 32 MHz using its internal 16 MHz HSI oscillator with PLL multiplication or external crystal sources. This frequency is sustained across the full –40 °C to +125 °C range and 1.65–3.6 V supply, delivering 0.95 DMIPS/MHz performance per ARM's CoreMark methodology.

Does the STM32L071K8U3 support hardware encryption?

No, the STM32L071K8U3 does not include hardware cryptographic accelerators. It lacks AES, DES, or SHA engines. For secure firmware updates or encrypted communications, software libraries (e.g., Mbed TLS) must be used - though this increases CPU load and power consumption versus hardware-accelerated alternatives like the STM32L072K8U3.

How many I/O pins are 5V tolerant on the STM32L071K8U3?

26 of the 28 general-purpose I/O pins on the STM32L071K8U3 are 5V tolerant (all PA and PB pins except PA12, PA13, PA14, PA15, and PB12). This allows direct interfacing with 5V logic peripherals such as legacy sensors or industrial I/O modules without external level-shifting circuitry.

Can the internal EEPROM be used for storing calibration data across power cycles?

Yes, the 6 KB internal EEPROM supports 100,000 write/erase cycles and guarantees data retention for 20 years at 85 °C. It includes built-in ECC for bit-error correction and sector protection against accidental writes - making it suitable for storing factory-calibrated sensor offsets, user configuration, or device-specific identifiers that persist through power loss.