STMicroelectronics STM32L072KBU3

Overview

STM32L072KBU3 from STMicroelectronics is an ultra-low-power 32-bit Arm® Cortex®-M0+ microcontroller with 192 KB Flash, 20 KB SRAM, and 6 KB EEPROM, operating from 1.65 V to 3.6 V across –40 °C to +125 °C. It integrates USB 2.0 (crystal-less), dual 12-bit DACs, 12-bit ADC (1.14 Msps), two ultra-low-power comparators, and capacitive touch sensing-designed for battery-powered IoT sensor nodes requiring long runtime and analog signal conditioning.

For engineers reviewing the STM32L072KBU3 datasheet, STM32L072KBU3 pinout, STM32L072KBU3 application, or STM32L072KBU3 equivalent, key selection considerations include its 0.86 µA Stop mode + RTC + 20-KB RAM retention, 5 µs Flash wakeup time, 93 µA/MHz Run-mode efficiency, USB crystal-less capability, and 78 I/Os (5V tolerant) in a compact UFQFPN32 package.

Technical Context

The STM32L072KBU3 implements a single-core Arm Cortex-M0+ with Memory Protection Unit (MPU), supporting dynamic voltage scaling and clock frequencies up to 32 MHz. 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 at 0.86 µA.

Analog subsystem integration includes a 12-bit ADC with up to 16 channels (1.14 Msps), two buffered 12-bit DACs (down to 1.8 V operation), and two comparators with window mode and wake-up capability (down to 1.65 V). Clock management supports multiple internal sources (HSI16, HSI48, LSI, MSI, LSE) and external oscillators (1–25 MHz HSE, 32 kHz LSE), with HSI48 self-calibrated for USB timing accuracy.

Key Specifications

Pinout & Package

STM32L072KBU3 is housed in a 32-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN) package measuring 5 mm × 5 mm with 0.5 mm pitch and exposed thermal pad. The package supports reflow soldering and provides mechanical robustness for space-constrained industrial and portable designs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L072KBU3, the STM32L073RBT6 trades USB for CAN and expands I/O count in a larger package, while the STM32L432KCU6 upgrades to Cortex-M4F for compute-intensive workloads but increases standby current and eliminates crystal-less USB-making the KBU3 optimal for minimal-footprint, USB-connected, battery-critical designs.

Availability

STM32L072KBU3 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 and long-term production continuity.

Supply support for STM32L072KBU3 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 analog products for industrial, automotive, and consumer markets.

The STM32L0 series targets ultra-low-power embedded applications-specifically optimizing for sub-1 µA standby operation, rapid wake-up, and integrated analog peripherals in minimal footprint packages for energy-harvesting and battery-operated systems.

FAQ

What is the maximum operating frequency of the STM32L072KBU3?

The STM32L072KBU3 operates at up to 32 MHz using its internal HSI16 oscillator (factory-trimmed to ±1%) or external clock sources. Frequency scaling is supported via dynamic voltage scaling to maintain optimal power/performance balance across operating conditions.

Does the STM32L072KBU3 support hardware encryption or secure boot?

The STM32L072KBU3 includes a true random number generator (TRNG) and memory firewall protection for code/data isolation, but lacks dedicated AES or PKA accelerators. Secure boot is implemented via readout protection (RDP) levels and option byte configuration-not cryptographic signature verification.

Can the STM32L072KBU3 drive 5V-tolerant I/Os directly from 3.3V supply?

Yes-25 of its 32 I/Os are 5V tolerant regardless of VDD level (1.65–3.6 V). This allows direct interfacing with legacy 5V peripherals (e.g., sensors, displays) without level shifters, simplifying design and reducing bill-of-materials cost.

Is the USB interface fully functional without an external crystal?

Yes-the USB 2.0 full-speed interface uses the internally calibrated 48 MHz HSI48 RC oscillator, eliminating need for external crystal. Calibration is performed automatically at startup using the Clock Recovery System (CRS) and USB SOF packets, achieving ±0.25% accuracy required for USB compliance.