STMicroelectronics STM32L151C6U6A

Overview

STM32L151C6U6A 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 monitors, and smart utility meters requiring sub-µA standby operation.

For engineers reviewing the STM32L151C6U6A datasheet, STM32L151C6U6A pinout, STM32L151C6U6A application, or STM32L151C6U6A equivalent, key selection criteria include verified ultra-low-power mode current (0.28 µA Standby), USB 2.0 full-speed interface with internal 48 MHz PLL, capacitive touch sensing support (up to 20 channels), and 73 I/Os with 5V tolerance - all within a compact UFQFPN48 package.

Technical Context

The STM32L151C6U6A implements dynamic voltage scaling and multiple low-power modes (Stop, Standby, Low-power Run) managed by an integrated ultra-low-power BOR with five threshold levels and programmable voltage detector (PVD). Its clock system combines HSE (1–24 MHz), LSE (32.768 kHz RTC), HSI (16 MHz ±1%), LSI (37 kHz), and MSI (65 kHz–4.2 MHz) sources, plus a dedicated USB PLL.

Memory architecture includes ECC-protected Flash and EEPROM, 80-byte backup registers, and hardware CRC unit. Analog subsystem integrates two ultra-low-power comparators with wake-up capability, temperature sensor, VREFINT reference, and LCD driver - though LCD functionality is excluded in STM32L151x6/8/B-A variants per datasheet Table 1 and Section 3.9.

Key Specifications

Pinout & Package

STM32L151C6U6A is housed in a 48-pin Ultra-Fine Pitch Quad Flat No-lead (UFQFPN48) package, 7 × 7 mm, 0.5 mm pitch, with exposed thermal pad - optimized for space-constrained PCB layouts and thermal dissipation in sealed enclosures.

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 STM32L151C6U6A, STM32L051C6T6 sacrifices USB, DAC, and memory for lower cost and smaller footprint, while STM32L431CCU6 trades ultra-low-power efficiency for enhanced compute capability and FPU - making the L151 optimal for balanced analog-rich, battery-critical designs.

Availability

STM32L151C6U6A 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 assurance, and RoHS-compliant manufacturing.

Supply support for STM32L151C6U6A 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 - specifically engineered for battery-operated equipment where multi-year runtime, robust analog integration, and extended temperature operation (-40°C to +105°C) are mandatory design requirements.

FAQ

Does STM32L151C6U6A support USB device functionality without external crystal?

Yes. The part integrates an internal 48 MHz PLL fed by the HSE or MSI clock, enabling full-speed USB 2.0 device operation without an external 48 MHz crystal. PA11/PA12 serve as dedicated D+/D− pins with internal pull-ups, reducing bill-of-materials and PCB area.

What is the maximum operating frequency when running from internal HSI RC oscillator?

The HSI oscillator is factory-trimmed to 16 MHz ±1% and supports CPU operation up to 32 MHz when used with the PLL (×2 multiplication). In non-PLL configurations, maximum core frequency is 16 MHz - sufficient for low-latency sensor polling and UART communication at 115.2 kbps.

How many I/O pins support 5V tolerance, and which voltage rail enables this?

73 of the 83 I/Os are 5V tolerant, enabled when VDDIO2 is supplied at 5 V. This is confirmed in Section 2.1 (Device overview) and Table 2 of the datasheet. Pins not marked as 5V-tolerant (e.g., USB, oscillator, BOOT0) must remain within 1.65–3.6 V.

Is the LCD controller functional on STM32L151C6U6A?

No. Per datasheet Section 3.9 and Table 1, LCD driver functionality is explicitly excluded from STM32L151x6/8/B-A devices. Only STM32L152x6/8/B-A variants include the LCD controller supporting up to 8×40 segments.