STMicroelectronics STM32L151C8U6A

Overview

STM32L151C8U6A from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller featuring 128 KB Flash, 32 KB SRAM, 4 KB EEPROM with ECC, 12-bit ADC (1 Msps, 24 channels), and dual 12-bit DACs - deployed in battery-powered medical sensors, portable industrial loggers, and smart utility meters requiring sub-µA standby operation.

For engineers reviewing the STM32L151C8U6A datasheet, STM32L151C8U6A pinout, STM32L151C8U6A application, or STM32L151C8U6A equivalent, key selection criteria include verified 0.28 µA Standby current, USB 2.0 full-speed support with internal 48 MHz PLL, 73 I/Os (5V-tolerant), and integrated touch sensing for capacitive UI interfaces.

Technical Context

The STM32L151C8U6A integrates a Cortex-M3 core running up to 32 MHz with MPU, dynamic voltage scaling across six low-power modes (Run, Sleep, Low-power Run, Stop, Standby), and hardware-accelerated peripherals including CRC unit and 96-bit unique ID. Its power architecture supports 1.65–3.6 V operation and -40°C to +105°C extended temperature range.

It embeds dual ultra-low-power comparators with window mode and wake-up capability, a temperature sensor with calibration data, and VREFINT reference - all functional down to 1.8 V supply. The USB interface uses an internal PLL clocked from HSE or MSI, eliminating external crystal dependency for USB timing.

Key Specifications

Pinout & Package

STM32L151C8U6A is housed in a 48-pin UFQFPN package (7 × 7 mm, 0.5 mm pitch) with exposed thermal pad. Pin functions are validated per STMicroelectronics DocID024330 Rev 5, Section 4 (Pin descriptions), supporting full GPIO remapping across 16 external interrupt vectors.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar ultra-low-power ARM Cortex-M3 microcontroller applications.

Compared with STM32L151C8U6A, STM32L051C8T6 sacrifices USB and DAC for lower cost and smaller footprint, while STM32L431CCU6 trades EEPROM and ultra-low standby for Cortex-M4F performance and larger memory - making the L151 optimal for USB-enabled, analog-rich, long-life battery systems.

Availability

STM32L151C8U6A is available at Aetrix Electronics and suitable for portable medical devices, smart utility meters, and industrial wireless sensor networks requiring stable component supply, long-term lifecycle support, and guaranteed traceability.

Supply support for STM32L151C8U6A 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 STM32L1 series targets ultra-low-power embedded applications demanding multi-year battery life, robust analog integration, and certified security features - optimized for wearables, metering, and IoT edge nodes.

FAQ

Does STM32L151C8U6A support USB device functionality without external crystal?

Yes. The part integrates an internal 48 MHz PLL that can be clocked from either the high-speed external oscillator (HSE) or the multispeed internal oscillator (MSI), enabling full-speed USB 2.0 device operation without requiring an external 48 MHz crystal - reducing BOM count and PCB area.

What is the maximum operating temperature and voltage range for reliable EEPROM writes?

The 4 KB EEPROM supports 100,000 write/erase cycles and 20-year data retention at 85°C. Writes are guaranteed across the full supply range (1.65–3.6 V) and temperature range (-40°C to +105°C), with built-in ECC ensuring bit-error correction during read-after-write verification.

How many I/O pins support 5V tolerance, and are they configurable per-pin?

73 of the 83 GPIOs are 5V-tolerant, covering all pins except those dedicated to USB (PA11/PA12), oscillator inputs (PH0/PH1), and BOOT0. Tolerance is inherent to the silicon structure - no configuration register is required to enable it, and it remains active in all reset and low-power states.

Can the capacitive sensing controller operate during Stop mode?

No. The CSD peripheral requires the APB1 clock and is disabled in Stop mode. However, the two ultra-low-power comparators remain active and can be configured to monitor analog inputs and generate wakeup events - providing low-power threshold detection without full MCU wake-up.