STMicroelectronics STM32L071KBU3TR

Overview

STM32L071KBU3TR from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in UFQFPN32 (5×5 mm) package, featuring 192 KB Flash with ECC, 20 KB SRAM, 6 KB EEPROM, 12-bit ADC (1.14 Msps), and operation down to 1.65 V. It delivers 0.86 µA Stop mode + RTC + RAM retention and supports 41 µA ADC conversion at 10 ksps - ideal for battery-powered sensor nodes and portable medical devices.

For engineers reviewing the STM32L071KBU3TR datasheet, STM32L071KBU3TR pinout, STM32L071KBU3TR application, or STM32L071KBU3TR equivalent, key selection criteria include ultra-low-power sleep current, integrated EEPROM endurance (100k cycles), 32-pin compact footprint, and dual ultra-low-power comparators with wake-up capability below 1.65 V.

Technical Context

The STM32L071KBU3TR implements a Cortex-M0+ core with Memory Protection Unit (MPU), operating from 32 kHz to 32 MHz with 0.95 DMIPS/MHz performance. Its power architecture includes five low-power modes (Run, Sleep, Low-power Run/Sleep, Stop, Standby), each with distinct peripheral availability and current profiles - e.g., Stop mode retains RTC and 20 KB RAM while drawing only 0.43 µA.

Clock management integrates multiple sources: HSE (1–25 MHz), LSE (32 kHz RTC), HSI16 (16 MHz ±1%), LSI (37 kHz), MSI (65 kHz–4.2 MHz), and PLL for CPU clock scaling. Analog subsystem includes two independent ultra-low-power comparators with window mode and wake-up capability, plus temperature sensor and internal voltage reference (VREFINT) calibrated for ADC accuracy.

Key Specifications

Pinout & Package

STM32L071KBU3TR uses the UFQFPN32 (5×5 mm) package with 32-pin layout, optimized for minimal PCB area and thermal performance in low-power designs. Pin functions are validated per STMicroelectronics DS10690 Rev 7 Section 4 (Pin descriptions) and Table 15 (STM32L071xxx pin definition).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L072KBU3TR, the STM32L071KBU3TR trades CAN for lower unit cost and identical ultra-low-power metrics; versus STM32L031K6U3TR, it adds 6 KB EEPROM and doubles Flash/SRAM - critical for OTA-capable, long-life IoT deployments.

Availability

STM32L071KBU3TR is available at Aetrix Electronics and suitable for smart utility metering, wearable health monitors, industrial wireless sensor nodes, and asset tracking beacons requiring stable component supply across multi-year production cycles.

Supply support for STM32L071KBU3TR 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 ICs, sensors, and analog components for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications demanding multi-year battery life, integrated nonvolatile memory, and robust operation from 1.65 V - with design focus on energy harvesting, portable medical, and smart infrastructure endpoints.

FAQ

What is the maximum operating frequency and corresponding power consumption in Run mode?

The STM32L071KBU3TR operates up to 32 MHz with dynamic voltage scaling. At 32 MHz and 3.3 V, typical Run mode current is 93 µA/MHz (≈3.0 mA total), verified per DS10690 Rev 7 Table 29. This includes active core, Flash, and SRAM; peripheral enablement increases current linearly based on usage.

Does STM32L071KBU3TR support hardware encryption or secure boot features?

No - the STM32L071KBU3TR 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. For built-in crypto, consider STM32L4/L5 series or STM32G071 with AES-128.

Can the 6 KB EEPROM be used for storing calibration data across power cycles?

Yes - the 6 KB data EEPROM is designed for persistent storage with 100,000 write/erase cycles and guaranteed 20-year data retention at 55°C (DS10690 Rev 7 Table 52). It supports byte/word/sector erase and ECC protection, making it suitable for factory calibration coefficients, user preferences, and runtime configuration parameters.

What debug interfaces are supported, and is SWD accessible on the UFQFPN32 package?

Serial Wire Debug (SW-DP) is fully supported via dedicated PA13 (SWDIO) and PA14 (SWCLK) pins, both exposed on the UFQFPN32 package per pinout Table 15. No JTAG support is provided. These pins are 5V-tolerant and require no level-shifting when interfacing with standard ST-LINK/V2 debug probes.