STMicroelectronics STM32L151C8U6

Overview

STM32L151C8U6 from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller featuring 64 KB Flash, 10 KB SRAM, 4 KB EEPROM with ECC, 12-bit ADC (1 Msps, 16 channels), and dual 12-bit DACs. It operates from 1.65–3.6 V, achieves 0.57 µA Stop mode current, and supports USB 2.0 Full-Speed via internal 48 MHz PLL - deployed in battery-powered medical sensors and portable industrial data loggers.

For engineers reviewing the STM32L151C8U6 datasheet, STM32L151C8U6 pinout, STM32L151C8U6 application, or STM32L151C8U6 equivalent, key selection criteria include ultra-low standby power (0.3 µA), integrated EEPROM endurance (100k cycles), USB + LCD-capable peripheral set, and UFBGA48 package compatibility with space-constrained PCB layouts.

Technical Context

The device implements dynamic voltage scaling across six low-power modes (Run, Sleep, Low-power Run/Sleep, Stop, Standby), with hardware-accelerated wake-up from Stop mode in under 8 µs. Its memory subsystem includes ECC-protected Flash and true EEPROM, enabling reliable firmware updates and parameter storage without external components.

Clock architecture integrates five oscillators: HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz ±1%), LSI (37 kHz), and MSI (65 kHz–4.2 MHz), plus a programmable PLL for USB clock generation. Analog subsystem combines two ultra-low-power comparators with window mode and wake-up capability, alongside temperature sensor and VREFINT calibration.

Key Specifications

Pinout & Package

STM32L151C8U6 is housed in a 48-pin Ultra Fine Pitch Ball Grid Array (UFBGA48) package with 0.5 mm ball pitch and 7 × 7 mm footprint. The package supports 36 I/Os (32 5V-tolerant), VDD/VSS power pairs distributed for noise suppression, and dedicated VBAT, VREF+, VREF−, and VSSA pins for precision analog operation.

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 STM32L151C8U6, STM32L051K8U6 sacrifices EEPROM and USB for lower cost and smaller die size, while STM32L431CCU6 trades ultra-low-power efficiency for Cortex-M4F performance and larger memory - making STM32L151C8U6 optimal for battery-limited applications requiring both USB and reliable nonvolatile storage.

Availability

STM32L151C8U6 is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, industrial wireless sensor nodes, and portable gas detectors requiring stable component supply across long product lifecycles.

Supply support for STM32L151C8U6 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 demanding extended battery life, robust memory reliability, and rich analog integration - especially in medical, metering, and portable industrial equipment.

FAQ

Does STM32L151C8U6 support USB device mode without external crystal?

Yes. The device integrates an internal 48 MHz PLL fed by the HSI RC oscillator, enabling full-speed USB 2.0 device operation without an external crystal. This reduces BOM count and board area - confirmed in Section 3.4 and Table 33 of the datasheet. USB enumeration is supported in all standard device classes including CDC and HID.

What is the guaranteed endurance of the on-chip EEPROM?

The 4 KB on-chip EEPROM is rated for 100,000 write/erase cycles and 20-year data retention at 55°C, with built-in ECC for single-bit error correction and detection. This specification is validated per Table 36 in the datasheet and eliminates need for external EEPROM in firmware parameter storage.

Can all 36 GPIOs be used simultaneously in the UFBGA48 package?

No. While the UFBGA48 variant provides 36 I/O pins, 4 pins (BOOT0, NRST, VDDA, VSSA) are dedicated to system functions and cannot be repurposed as general-purpose I/Os. The maximum usable GPIO count is 32, all of which are 5V-tolerant and support remappable alternate functions per Table 8.

How does the ultra-low-power comparator differ from standard comparators?

This comparator consumes only 190 nA typical in active mode and supports window mode with independent upper/lower thresholds. It can wake the MCU from Stop mode in <3 µs - verified in Table 60 and Section 3.12. Its rail-to-rail input range and hysteresis control make it ideal for battery voltage monitoring and sensor threshold detection.