STMicroelectronics STM32L151R8T6ATR

Overview

STM32L151R8T6ATR 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 IoT sensors, portable medical monitors, and smart utility meters requiring sub-µA standby operation.

For engineers reviewing the STM32L151R8T6ATR datasheet, STM32L151R8T6ATR pinout, STM32L151R8T6ATR application, or STM32L151R8T6ATR equivalent, key selection criteria include ultra-low-power mode timing (0.28 µA Standby), integrated EEPROM endurance (100k cycles), USB 2.0 full-speed support with internal 48 MHz PLL, and 73 I/Os with 5V tolerance - all within LQFP64 package constraints.

Technical Context

The STM32L151R8T6ATR implements a 32-bit ARM Cortex-M3 core running at up to 32 MHz with MPU, supported by dynamic voltage scaling across five power modes. Its clock system integrates HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz ±1%), LSI (37 kHz), and MSI (65 kHz–4.2 MHz) sources plus a USB-capable PLL.

Analog subsystem includes two ultra-low-power comparators with window mode and wake-up capability, temperature sensor, VREFINT reference, and dual buffered 12-bit DACs - all operable down to 1.8 V supply. The 7-channel DMA controller enables zero-CPU-load peripheral transfers for ADC, DAC, USB, and communication interfaces.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad - optimized for compact PCB layout and thermal dissipation in space-constrained industrial modules.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L151R8T6ATR, STM32L071RBT6 reduces cost and active power but sacrifices EEPROM and USB; STM32L431RBT6 increases compute headroom and standby efficiency yet requires external nonvolatile storage and narrower supply tolerance.

Availability

STM32L151R8T6ATR is available at Aetrix Electronics and suitable for battery-powered IoT endpoints, portable medical instruments, and smart utility meters requiring stable component supply across multi-year production cycles.

Supply support for STM32L151R8T6ATR 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 automotive semiconductors since 1987.

The STM32L1 series targets ultra-low-power embedded applications - emphasizing energy efficiency, integrated peripherals (EEPROM, LCD, USB), and robust operation from -40°C to +105°C for industrial and medical use cases.

FAQ

What is the maximum operating frequency and core type of the STM32L151R8T6ATR?

The STM32L151R8T6ATR features an ARM Cortex-M3 32-bit core with a maximum CPU frequency of 32 MHz, delivering 1.25 DMIPS/MHz (Dhrystone 2.1). It supports dynamic voltage scaling to maintain performance across multiple low-power modes, including Run, Sleep, Low-power Run, Stop, and Standby - with full 32 MHz operation achievable in Run mode at 3.3 V.

Does the STM32L151R8T6ATR include embedded EEPROM, and what are its endurance specifications?

Yes, it integrates 4 KB of true EEPROM with built-in ECC protection. This memory supports 100,000 write/erase cycles and guarantees data retention for 10 years at 85°C (or 40 years at 25°C), eliminating the need for external serial EEPROM in applications requiring frequent parameter updates like calibration data or usage logs.

Can the STM32L151R8T6ATR operate in USB device mode without an external crystal?

Yes - it includes an internal 48 MHz PLL dedicated to USB full-speed operation, allowing USB device functionality without an external crystal. The PLL locks to the internal 16 MHz HSI RC oscillator (±1% factory-trimmed), enabling plug-and-play USB connectivity while reducing BOM cost and PCB footprint.

How many I/O pins are 5V tolerant, and which packages support this feature?

73 of the 83 total I/Os are 5V tolerant, specifically those on GPIO ports PA–PE excluding analog-dedicated pins (e.g., ADC inputs). This applies to the LQFP64 package (STM32L151R8T6ATR), enabling direct interfacing with legacy 5V logic, displays, or sensors without level shifters - confirmed in Section 3.13 of the datasheet and Table 43 (I/O static characteristics).