STMicroelectronics STM32L151CBU6

Overview

STM32L151CBU6 from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller featuring 128 KB Flash, 16 KB SRAM, 4 KB EEPROM with ECC, 12-bit ADC (1 Msps, 24 channels), and dual 12-bit DACs - deployed in battery-powered IoT sensors and portable medical monitors requiring sub-1 µA standby current and < 8 µs wake-up.

For engineers reviewing the STM32L151CBU6 datasheet, STM32L151CBU6 pinout, STM32L151CBU6 application, or STM32L151CBU6 equivalent, key selection criteria include verified ultra-low-power mode current (0.3 µA Standby), USB 2.0 full-speed support with internal 48 MHz PLL, and capacitive touch sensing capability across up to 20 channels.

Technical Context

The STM32L151CBU6 integrates a 32 MHz ARM Cortex-M3 core with MPU, dynamic voltage scaling, and five low-power modes (Run, Sleep, Low-power Run, Stop, Standby) optimized for energy-constrained applications. Its clock system combines HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz ±1%), LSI (37 kHz), and MSI (65 kHz–4.2 MHz) sources, plus a dedicated USB PLL.

Analog subsystem includes two ultra-low-power comparators with window mode and wake-up capability, temperature sensor, VREFINT reference, and hardware-accelerated CRC unit. Memory protection unit (MPU), 96-bit unique ID, and pre-programmed USART bootloader enable secure, traceable embedded deployment.

Key Specifications

Pinout & Package

STM32L151CBU6 uses the UFQFPN48 (7 × 7 mm, 0.5 mm pitch) package with 48 pins, supporting 37 I/Os (31 5V-tolerant), VDD/VSS power pairs, dedicated reset (NRST), and configurable boot pins (BOOT0/BOOT1). Pin functions include multiple alternate-function mappings for USART, SPI, I²C, USB D+/D−, ADC inputs, DAC outputs, and touch sensing channels.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L051K8U6, the STM32L151CBU6 adds USB, EEPROM, and dual DACs at modest current cost; versus STM32L431CCU6, it trades peak performance for guaranteed sub-1 µA standby and integrated nonvolatile storage - making it optimal for longevity-critical, mixed-signal edge endpoints.

Availability

STM32L151CBU6 is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, industrial wireless sensor nodes, and portable diagnostic devices requiring stable component supply across multi-year production cycles.

Supply support for STM32L151CBU6 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 automotive semiconductors since 1987.

The STM32L1 series targets ultra-low-power embedded applications - emphasizing energy efficiency, integrated analog peripherals, and long-term reliability in battery-operated and energy-harvesting systems.

FAQ

What is the maximum operating frequency and core architecture of the STM32L151CBU6?

The STM32L151CBU6 features an ARM Cortex-M3 32-bit RISC core rated for up to 32 MHz operation, delivering 1.25 DMIPS/MHz (Dhrystone 2.1). It includes a Memory Protection Unit (MPU) and supports Thumb-2 instruction set for efficient code density and deterministic real-time execution.

Does the STM32L151CBU6 support USB functionality without external components?

Yes - the STM32L151CBU6 integrates a full-speed USB 2.0 transceiver with internal 48 MHz PLL, requiring only passive termination (1.5 kΩ pull-up on D+) and standard USB connector wiring. No external PHY or crystal is needed for basic device enumeration and CDC/DFU class operation.

How many analog-to-digital converter (ADC) channels does the STM32L151CBU6 provide, and what is its resolution and speed?

The STM32L151CBU6 includes a single 12-bit ADC with up to 24 input channels (10 dedicated, 14 multiplexed), capable of 1 MSPS sampling rate. It supports hardware oversampling, scan mode, and built-in temperature sensor and VREFINT channel for system-level calibration.

What ultra-low-power modes are available, and what are their typical current draws?

The STM32L151CBU6 offers five low-power modes: Standby (0.3 µA, 3 wakeup pins), Standby+RTC (0.9 µA), Stop (0.57 µA, 16 wakeup lines), Stop+RTC (1.2 µA), and Low-power Run (9 µA). All modes retain RAM content and support fast wake-up (< 8 µs from Stop/Standby) via configurable event triggers.