STMicroelectronics STM32L151UCY7TR

Overview

STM32L151UCY7TR from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller with 256KB Flash, 32KB SRAM, 8KB EEPROM, integrated LCD driver (up to 8×40 segments), USB 2.0 interface, and dual 12-bit DACs. It operates from 1.65–3.6 V across –40 °C to +105 °C and delivers 185 µA/MHz in Run mode, targeting battery-powered medical sensors and portable instrumentation.

For engineers reviewing the STM32L151UCY7TR datasheet, STM32L151UCY7TR pinout, STM32L151UCY7TR application, or STM32L151UCY7TR equivalent, key selection criteria include its 0.44 µA Stop mode current, 8.6 µA Low-power run mode, 12-bit ADC with 25 channels and 1 Msps sampling, dual operational amplifiers, and WLCSP63 package with 63 I/O terminals - all validated for energy-constrained embedded designs.

Technical Context

The STM32L151UCY7TR implements dynamic voltage scaling (DVS) with three power modes (UHP, HP, LP) to optimize performance versus current draw. Its Cortex-M3 core runs at up to 32 MHz using multiple clock sources: HSE (1–24 MHz), LSE (32.768 kHz RTC), HSI (16 MHz ±1%), LSI (37 kHz), and MSI (65 kHz–4.2 MHz), with a dedicated 48 MHz PLL for USB.

Analog subsystem integration includes two rail-to-rail op-amps, two ultra-low-power comparators with window mode and wake-up capability, a 12-bit ADC (25 channels, 1 Msps), two buffered 12-bit DACs, temperature sensor, and internal VREFINT - all functional down to 1.8 V supply, enabling single-supply mixed-signal operation without external signal conditioning.

Key Specifications

Pinout & Package

STM32L151UCY7TR uses a 63-ball WLCSP (Wafer-Level Chip-Scale Package) with 0.4 mm pitch, measuring 2.49 × 2.49 mm. The package supports 63 I/O terminals including 70 general-purpose I/Os (5V-tolerant on 70 pins), all mappable to 16 external interrupt vectors, and features dedicated pins for USB D+/D−, LCD segment/common outputs, and ultra-low-leakage analog inputs.

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 STM32L151UCY7TR, STM32L431CCU6 trades EEPROM and ultra-low Stop current for Cortex-M4F compute power and larger Flash, while EFM32PG12B500F1024GL125 achieves lower deep-sleep current but sacrifices USB connectivity and integrated display support - making STM32L151UCY7TR optimal for compact, feature-integrated, battery-powered human-interface devices.

Availability

STM32L151UCY7TR is available at Aetrix Electronics and suitable for portable medical sensors, smart utility meters, industrial wireless nodes, and wearable health trackers requiring stable component supply across extended product lifecycles.

Supply support for STM32L151UCY7TR 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, emphasizing energy efficiency, integrated analog peripherals, and long-life battery operation - specifically engineered for medical, metering, and portable industrial equipment.

FAQ

What is the maximum operating frequency and core type of the STM32L151UCY7TR?

The STM32L151UCY7TR features an ARM Cortex-M3 32-bit core with a maximum CPU frequency of 32 MHz. It achieves 1.25 DMIPS/MHz (Dhrystone 2.1) and includes a Memory Protection Unit (MPU) for secure memory access control. This core is optimized for deterministic real-time execution in ultra-low-power environments, supporting both Thumb-2 and ARM instruction sets.

Does the STM32L151UCY7TR include hardware-based security features for firmware protection?

The STM32L151UCY7TR does not include cryptographic accelerators or secure boot engines. Its primary hardware security features are the Memory Protection Unit (MPU) for runtime memory region enforcement and read-out protection (RDP) levels that prevent unauthorized debug access and Flash memory dumping. These features support basic firmware integrity and intellectual property protection but do not provide AES/SHA acceleration or secure key storage.

Can the STM32L151UCY7TR drive a segment LCD without external components?

Yes - the STM32L151UCY7TR integrates a full LCD controller supporting up to 8 commons and 40 segments, with programmable contrast, blinking mode, and an internal step-up converter generating the VLCD bias voltage. This eliminates the need for external LCD bias ICs or charge pumps, reducing BOM cost and PCB area in portable display applications.

What are the supported clock sources and their key specifications?

The STM32L151UCY7TR supports six clock sources: HSE (1–24 MHz crystal), LSE (32.768 kHz RTC crystal), HSI (16 MHz RC, ±1% factory-trimmed), LSI (37 kHz RC), MSI (65 kHz–4.2 MHz multispeed RC), and a dedicated 48 MHz PLL for USB. All sources are switchable at runtime, and the LSE includes hardware calibration for ±1 ppm RTC accuracy over temperature.