STMicroelectronics STM32L071KZU3

Overview

STM32L071KZU3 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller in a 32-pin UFQFPN package, featuring 192 KB Flash, 20 KB SRAM, 6 KB EEPROM with ECC, 12-bit ADC (1.14 Msps), and operation 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 runtime and RTC-backed data logging.

For engineers reviewing the STM32L071KZU3 datasheet, STM32L071KZU3 pinout, STM32L071KZU3 application, or STM32L071KZU3 equivalent, key selection criteria include standby current (0.29 µA), 5 µs Flash wakeup time, 78 5V-tolerant I/Os, and integrated ultra-low-power comparators with wake-up capability down to 1.65 V.

Technical Context

The STM32L071KZU3 implements a dual-bank Flash architecture with read-while-write capability and hardware ECC for both Flash and EEPROM, enabling robust firmware updates and nonvolatile data storage in field-deployed devices. Its power management includes five BOR thresholds, programmable voltage detector (PVD), and three internal RC oscillators (37 kHz, 65 kHz–4.2 MHz, 16 MHz ±1%) supporting dynamic voltage scaling.

Peripherals are routed via an interconnect matrix enabling concurrent DMA-driven operations: 7-channel DMA services ADC, USART, SPI, I2C, and timers; 11 timers include two 16-bit advanced timers with up to 4 channels, one ultra-low-power LPTIM, and dual watchdogs (independent + window) for safety-critical timing supervision.

Key Specifications

Pinout & Package

STM32L071KZU3 uses a 32-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN) package, 5 mm × 5 mm, 0.5 mm pitch, with exposed thermal pad. Pin functions are validated per STMicroelectronics datasheet DS10690 Rev 7, Section 4 (Pin descriptions).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L071KZU3, STM32L072KZU3 adds hardware crypto for secure boot and communication, while STM32L071KBU3 trades the compact UFQFPN thermal performance for LQFP manufacturability-both retain identical ultra-low-power behavior and peripheral compatibility.

Availability

STM32L071KZU3 is available at Aetrix Electronics and suitable for smart utility metering, wireless sensor nodes, industrial predictive maintenance, and medical wearable patches requiring stable component supply and long-term lifecycle support.

Supply support for STM32L071KZU3 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 Access line targets ultra-low-power embedded applications demanding extended battery life, robust memory integrity, and rich analog integration-optimized for cost-sensitive, size-constrained IoT endpoints.

FAQ

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

The STM32L071KZU3 operates up to 32 MHz. At 32 MHz with code executing from Flash, typical current consumption is 93 µA/MHz (≈2.98 mA total), measured at 3.0 V and 25 °C per DS10690 Rev 7 Table 29. This value scales linearly with clock speed and varies with voltage and temperature per Tables 29–32.

Does STM32L071KZU3 support hardware encryption or secure boot features?

No, STM32L071KZU3 does not include hardware cryptographic accelerators. It lacks AES, DES, or PKA engines. Secure boot must be implemented in software using stored keys and signature verification routines. For hardware-assisted security, consider STM32L072KZU3, which integrates AES-128 and public-key accelerators.

Can the internal 16 MHz RC oscillator (HSI16) be used as the system clock without calibration?

Yes, HSI16 is factory-trimmed to ±1% accuracy at 25 °C and 3.3 V, making it suitable as the default system clock without external crystal or runtime calibration. For higher precision (e.g., USB or audio timing), use HSE (1–25 MHz crystal) or calibrate HSI16 against LSE using the RCC calibration register per Section 3.5 of DS10690.

How many I/O pins support 5V tolerance, and what is the absolute maximum rating for those pins?

78 I/O pins are 5V tolerant when VDD is powered (1.65–3.6 V). Per DS10690 Rev 7 Table 22, the absolute maximum voltage on any 5V-tolerant pin is VDD + 4 V, with VDD ≥ 1.65 V. This allows direct interfacing with 5V logic without external level shifters, provided VDD remains within specification.