STMicroelectronics STM32L422CBU6

Overview

STM32L422CBU6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, 128KB flash, 40KB SRAM, and integrated analog peripherals including dual 12-bit ADCs (5 Msps), one operational amplifier with PGA, and one ultra-low-power comparator. It operates from 1.71–3.6 V across –40 °C to 85 °C and delivers 100 DMIPS at 80 MHz - used in battery-powered IoT sensor nodes requiring long runtime and precision analog sensing.

For engineers reviewing the STM32L422CBU6 datasheet, STM32L422CBU6 pinout, STM32L422CBU6 application, or STM32L422CBU6 equivalent, key selection factors include its 245 nA Standby-with-RTC current, USB 2.0 full-speed crystal-less capability, AES-128/256 hardware acceleration, and support for capacitive touch sensing up to 12 channels.

Technical Context

The device integrates an Adaptive Real-time Accelerator (ART Accelerator™) enabling zero-wait-state execution from flash at 80 MHz, alongside a memory protection unit (MPU) and interconnect matrix for deterministic peripheral arbitration. Its FlexPowerControl architecture supports seven low-power modes, including Stop 2 (0.7 µA) and Shutdown (16 nA), with 4 µs wake-up latency.

Clock system includes four internal oscillators (HSI16, MSI, LSI, HSI48) plus external 4–48 MHz HSE and 32 kHz LSE, with auto-trimming and PLL for system clock generation. The 32-pin UFQFPN package hosts 25 I/Os - all 5 V-tolerant - and supports SWD/JTAG debug via dedicated pins.

Key Specifications

Pinout & Package

STM32L422CBU6 is housed in a 32-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN32) package measuring 5 × 5 mm with 0.5 mm pitch. The package supports hand-soldering and automated assembly, features exposed thermal pad for improved heat dissipation, and complies with ECOPACK2 environmental standards.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L432KCU6, the STM32L422CBU6 trades flash capacity and DFSDM for USB 2.0 crystal-less support - ideal for direct PC-connected diagnostics tools. Against STM32L552CEU6, it offers lower active and standby current at the expense of TrustZone-based security features.

Availability

STM32L422CBU6 is available at Aetrix Electronics and suitable for battery-powered IoT sensor nodes, portable medical devices, smart home interfaces, and industrial wireless monitoring systems requiring stable component supply and long-term manufacturability.

Supply support for STM32L422CBU6 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 components for industrial, automotive, and consumer markets.

The STM32L4 series targets ultra-low-power embedded applications demanding high performance-per-microwatt, featuring advanced power gating, adaptive voltage scaling, and integrated analog for sensor edge processing.

FAQ

What is the maximum operating frequency and corresponding performance metric?

The STM32L422CBU6 runs at up to 80 MHz with the Arm Cortex-M4 core delivering 100 DMIPS and 273.55 CoreMark® (3.42 CoreMark/MHz). This performance is sustained with zero wait-states thanks to the ART Accelerator™, which caches flash accesses - verified in DS12470 Rev 6 Section 3.2 and Table 10.

Does STM32L422CBU6 support USB without an external crystal?

Yes - it integrates a 48 MHz HSI48 oscillator with clock recovery system (CRS) that synchronizes to USB SOF packets, enabling full-speed (12 Mbit/s) USB 2.0 operation without external crystal or capacitors. This is confirmed in Section 3.27 and Table 12 of DS12470 Rev 6.

How many I/O pins are available in the UFQFPN32 package, and what is their voltage tolerance?

The UFQFPN32 package provides 25 general-purpose I/O pins (PA0–PA15, PB0–PB12, PC13–PC15), all 5 V-tolerant even when VDD is as low as 1.71 V. Pin count and tolerance are specified in Table 14 (Pin Definitions) and Section 3.12 of DS12470 Rev 6.

What low-power modes offer RTC functionality, and what are their typical currents?

Standby mode with RTC consumes 245 nA, and Stop 2 mode with RTC consumes 0.95 µA - both retain RTC calendar, alarms, and 32×32-bit backup registers. These values are measured at 25 °C, VDD = 3.3 V, and published in Tables 36 and 33 of DS12470 Rev 6 Section 6.3.5.