STMicroelectronics STM32L151CCU6TR

Overview

STM32L151CCU6TR from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller featuring 256 KB Flash, 32 KB SRAM, 8 KB EEPROM with ECC, integrated 12-bit ADC (1 Msps, 25 channels), and dual 12-bit DACs - deployed in battery-powered IoT sensors and portable medical monitors requiring sub-µA standby current and RTC-backed wake-up.

For engineers reviewing the STM32L151CCU6TR datasheet, STM32L151CCU6TR pinout, STM32L151CCU6TR application, or STM32L151CCU6TR equivalent, key selection criteria include verified 0.29 µA Standby mode (3 wakeup pins), USB 2.0 full-speed interface with internal 48 MHz PLL, LCD driver support (excluded in STM32L151xC variants), and 70 I/Os with 5V tolerance - all validated for industrial temperature range (-40 °C to +105 °C).

Technical Context

The STM32L151CCU6TR implements dynamic voltage scaling across six low-power modes (Run, Sleep, Low-power Run, Low-power Sleep, Stop, Standby), with dedicated power domains for analog peripherals and real-time clock. Its memory protection unit (MPU) enforces privilege levels for secure firmware execution, while the pre-programmed USB/USART bootloader enables field firmware updates without external programmer.

Clock architecture integrates five independent sources: HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz ±1%), LSI (37 kHz), and MSI (65 kHz–4.2 MHz), with a programmable PLL supporting CPU clock up to 32 MHz and USB clock at 48 MHz - all managed via RCC registers with fail-safe oscillator switching.

Key Specifications

Pinout & Package

STM32L151CCU6TR is housed in a 48-pin UFQFPN package (7 × 7 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are defined per STM32L151xC datasheet Section 4 (Pin descriptions), with VDD/VSS pairs distributed for noise suppression and dedicated VREF+/- pins for ADC/DAC reference stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L151CCU6TR, the STM32L431CCU6 trades EEPROM and USB for FPU and security features, while the EFM32PG12B500F1024GL125 achieves deeper sleep at the cost of interface flexibility - making the L151 optimal for USB-connected, EEPROM-dependent, battery-constrained designs.

Availability

STM32L151CCU6TR is available at Aetrix Electronics and suitable for smart utility meters, portable ECG monitors, industrial wireless sensor nodes, and asset tracking beacons requiring stable component supply across extended product lifecycles.

Supply support for STM32L151CCU6TR 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, MEMS, and automotive semiconductors since 1987.

The STM32L1 series targets ultra-low-power embedded applications demanding multi-year battery life, robust analog integration, and industrial-grade reliability - specifically engineered for metering, portable healthcare, and wireless sensor endpoints.

FAQ

Does STM32L151CCU6TR support USB device mode without an external crystal?

Yes. The part integrates an internal 48 MHz PLL that can lock to the 16 MHz HSI or 65 kHz–4.2 MHz MSI clock source, enabling full-speed USB 2.0 device operation without requiring an external 48 MHz crystal or oscillator - confirmed in Section 3.4 and Table 34 of the datasheet.

What is the maximum number of ADC channels usable simultaneously in continuous conversion mode?

The 12-bit ADC supports up to 25 external channels, but only 16 can be enabled in a single regular sequence. Simultaneous sampling across multiple channels is not supported; however, injected conversions allow prioritized sampling of up to 4 channels alongside regular sequences - detailed in Section 3.10 and Table 56.

How is the 8 KB EEPROM implemented, and does it require special erase/write procedures?

The 8 KB EEPROM is implemented as a dedicated memory block with hardware ECC and wear-leveling logic. It uses standard Flash programming instructions (via HAL_FLASHEx_DATAEEPROM_Unlock/Lock) and supports byte/word writes with automatic page erase - no external controller or software wear-leveling is needed, as specified in Section 3.7 and Table 36.

Can the STM32L151CCU6TR drive an LCD segment display?

No. The STM32L151CCU6TR belongs to the STM32L151xC line, which explicitly excludes the LCD controller peripheral per Section 2.1 and Table 1 of the datasheet. Only STM32L151xU and STM32L151xV variants integrate the LCD driver - this part supports only general-purpose I/O and analog peripherals.