STMicroelectronics STM32L433CBU6

Overview

STM32L433CBU6 from STMicroelectronics is an ultra-low-power Arm® Cortex®-M4 32-bit MCU with FPU, operating up to 80 MHz (100 DMIPS), featuring 128 KB flash, 64 KB SRAM, USB FS, LCD controller, and integrated SMPS support. It delivers 36 µA/MHz in SMPS-run mode, 280 nA Standby with RTC, and supports capacitive touch sensing for battery-powered portable instrumentation.

For engineers reviewing the STM32L433CBU6 datasheet, STM32L433CBU6 pinout, STM32L433CBU6 application, or STM32L433CBU6 equivalent, key selection criteria include ultra-low-power operation across Stop/Standby modes, LCD driving capability (8×40), dual 12-bit DACs, and CAN 2.0B interface compatibility in compact UFBGA64 packaging.

Technical Context

The STM32L433CBU6 integrates an Adaptive Real-time Accelerator (ART™) enabling zero-wait-state execution from flash at 80 MHz, alongside a memory protection unit (MPU) and dual PLLs supporting independent clock domains for USB, audio, and system timing. Its interconnect matrix enables concurrent peripheral access without bus contention.

Power architecture includes FlexPowerControl with configurable LDO/SMPS supply paths, batch acquisition mode (BAM) for sensor data collection during low-power states, and hardware parity on 16 KB of SRAM. The RTC features hardware calendar, calibration, and tamper detection-critical for time-stamped logging in edge-deployed devices.

Key Specifications

Pinout & Package

STM32L433CBU6 is housed in a 5×5 mm UFBGA64 package (A019 marking), with 48 user I/Os (most 5 V-tolerant), dedicated VBAT, VREF+, VREF-, and LCD segment/common pins routed to perimeter balls for optimal trace routing and EMI control.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L432KBU6, the STM32L433CBU6 adds LCD and CAN while doubling flash; versus STM32L476RGY6, it trades memory size and USB OTG for superior SMPS efficiency and smaller UFBGA64 footprint-making it optimal for cost-sensitive, battery-powered LCD displays with fieldbus needs.

Availability

STM32L433CBU6 is available at Aetrix Electronics and suitable for smart utility meters, portable medical devices, industrial HMI panels, and wireless sensor nodes requiring stable component supply across long-lifecycle deployments.

Supply support for STM32L433CBU6 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, designing and manufacturing microcontrollers, power management ICs, sensors, and analog chips for industrial, automotive, and consumer markets.

The STM32L4 series targets ultra-low-power embedded applications demanding high performance-per-milliwatt, with emphasis on battery longevity, integrated analog, and human-interface peripherals like LCD and touch sensing.

FAQ

What is the maximum operating temperature range for STM32L433CBU6?

The STM32L433CBU6 is qualified for operation from –40 °C to +105 °C (industrial grade), with extended testing confirming reliable functionality up to +125 °C in specific configurations. This rating applies to all package variants including UFBGA64, and is validated per JEDEC JESD47 stress-test standards.

Does STM32L433CBU6 support external memory expansion via Quad SPI?

Yes, STM32L433CBU6 includes a dedicated QUADSPI interface supporting up to 50 MHz clock frequency, XIP (execute-in-place) mode, and memory-mapped access to external NOR flash or RAM. It supports single/dual/quad I/O protocols and hardware encryption key storage for secure boot from external memory.

How many capacitive sensing channels does STM32L433CBU6 provide, and what topologies are supported?

The device integrates a hardware touch-sensing controller (TSC) with 21 capacitive sensing channels, supporting touchkey, linear touchpad, and rotary touchpad topologies. It includes built-in charge transfer measurement, spread-spectrum modulation, and automatic recalibration-enabling robust touch detection even under varying environmental conditions.

Can STM32L433CBU6 operate without an external crystal for USB functionality?

Yes, STM32L433CBU6 implements a crystal-less USB 2.0 Full-Speed interface using its internal 48 MHz RC oscillator with clock recovery system (CRS). This eliminates the need for an external 48 MHz crystal or oscillator, reducing BOM cost and PCB area while maintaining ±0.25% accuracy over voltage and temperature.