STMicroelectronics STM32L151UCY6DTR

Overview

STM32L151UCY6DTR 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 LCD controller (up to 8×40 segments), and USB 2.0 interface. It operates from 1.65 V to 3.6 V across –40 °C to +105 °C and delivers 1.25 DMIPS/MHz performance. It targets battery-powered portable instrumentation, smart sensors, and wearable medical devices requiring long runtime and on-chip analog integration.

For engineers reviewing the STM32L151UCY6DTR datasheet, STM32L151UCY6DTR pinout, STM32L151UCY6DTR application, or STM32L151UCY6DTR equivalent, key selection criteria include standby current (0.29 µA), 12-bit ADC (1 Msps, 25 channels), dual 12-bit DACs, ultra-low-power comparators with wake-up capability, and WLCSP63 package compatibility with capacitive touch sensing.

Technical Context

The STM32L151UCY6DTR implements dynamic voltage scaling and multiple low-power modes-Stop (0.44 µA), Standby (0.29 µA), and Low-power Run (8.6 µA)-with sub-8 µs wake-up latency. Its clock system integrates factory-trimmed 16 MHz HSI RC (±1%), 32 kHz LSE for RTC calibration, and a PLL generating 48 MHz for USB.

Analog subsystem includes two operational amplifiers, two ultra-low-power comparators (window mode + wake-up), 12-bit ADC with internal reference and temperature sensor, and dual buffered 12-bit DACs-enabling closed-loop sensor signal conditioning and precision actuator control without external components.

Key Specifications

Pinout & Package

STM32L151UCY6DTR uses a 63-ball WLCSP (Wafer-Level Chip-Scale Package) with 0.4 mm pitch, optimized for space-constrained applications such as wearables and compact IoT sensors. The package supports solder reflow per JEDEC J-STD-020 and features 48 user I/Os, including 16 external interrupt lines and 23 capacitive sensing channels.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L151UCY6DTR, STM32L412KBU6 trades EEPROM and LCD for FPU-enhanced computation, while EFM32PG12B500F1024GL125 offers deeper sleep and larger memory but removes integrated USB and display interfaces-making STM32L151UCY6DTR optimal for compact, self-contained sensor displays with firmware persistence.

Availability

STM32L151UCY6DTR is available at Aetrix Electronics and suitable for portable medical sensors, smart utility meters, and wearable fitness trackers requiring stable component supply, long-term lifecycle assurance, and wafer-level packaging for miniaturized designs.

Supply support for STM32L151UCY6DTR 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 analog products for industrial, automotive, and consumer markets.

The STM32L1 series targets ultra-low-power embedded applications demanding extended battery life, integrated analog peripherals, and robust firmware security-designed specifically for IoT edge nodes, portable healthcare, and energy-metering systems.

FAQ

Does STM32L151UCY6DTR support USB without an external crystal?

Yes. The device integrates a 48 MHz PLL fed by its internal 16 MHz HSI RC oscillator (±1% factory-trimmed), enabling full-speed USB 2.0 operation without an external crystal. This reduces BOM cost and PCB area-confirmed in Section 3.4 "Clock management" and Table 31 of the datasheet.

What is the maximum number of capacitive sensing channels supported?

The STM32L151UCY6DTR supports up to 23 capacitive sensing channels using its built-in touch sensing controller (TSC), as specified in Section 3.15 and Table 2 of the datasheet. All 23 channels operate in low-power mode with dedicated hardware scanning, requiring no CPU intervention during measurement.

How does the 8 KB EEPROM differ from standard Flash memory?

This is true EEPROM-not emulated in Flash-with dedicated ECC, 300k write/erase endurance, and guaranteed 20-year data retention at 85 °C. Unlike Flash, it supports byte-level writes and retains data during power loss without backup power, as detailed in Section 3.7 "Memories" and Table 36–37.

Is the WLCSP63 package RoHS and REACH compliant?

Yes. STM32L151UCY6DTR in WLCSP63 packaging meets RoHS Directive 2011/65/EU and REACH Regulation (EC) No. 1907/2006, with lead-free solderability and halogen-free materials. Compliance documentation is available in ST's official product change notices (PCN) and material declarations.