STMicroelectronics STM32L151R6T6A

Overview

STM32L151R6T6A 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 STM32L151R6T6A datasheet, STM32L151R6T6A pinout, STM32L151R6T6A application, or STM32L151R6T6A equivalent, key selection criteria include verified ultra-low-power mode current (0.28 µA Standby), USB 2.0 interface compliance, RTC+backup register retention, and 73 I/Os with 5V tolerance - all confirmed in ST's DocID024330 Rev 5 production datasheet.

Technical Context

This MCU implements dynamic voltage scaling across five low-power modes (Run, Sleep, Low-power Run, Stop, Standby), with hardware-accelerated power gating and a dedicated ultra-low-power regulator enabling 0.44 µA Stop mode with 16 wakeup lines. The Cortex-M3 core runs at up to 32 MHz with 1.25 DMIPS/MHz and includes a memory protection unit for secure firmware partitioning.

Clock architecture integrates six independent sources: HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz ±1%), LSI (37 kHz), MSI (65 kHz–4.2 MHz), and a USB PLL generating 48 MHz - all configurable via RCC registers without external components. Analog subsystem includes two ultra-low-power comparators with window mode and wake-up capability, plus temperature sensor and VREFINT calibration.

Key Specifications

Pinout & Package

LQFP64 package (10 × 10 mm, 0.5 mm pitch), 64-pin quad flat lead frame with exposed thermal pad - compatible with standard reflow profiles and automated optical inspection.

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 STM32L151R6T6A, STM32L051K8U6 sacrifices USB, DAC, and EEPROM for lower cost and smaller footprint, while STM32L431RCY6TR trades ultra-low-power efficiency for Cortex-M4F performance - making the L151 optimal for balanced USB-enabled, analog-rich, battery-critical applications.

Availability

STM32L151R6T6A is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, wireless sensor nodes, and portable diagnostic devices requiring stable component supply across multi-year production cycles.

Supply support for STM32L151R6T6A 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 - specifically engineered for battery-operated devices demanding long service life, integrated analog functionality, and industrial-grade reliability from -40°C to +105°C.

FAQ

What is the maximum operating frequency and associated power consumption of the STM32L151R6T6A?

The STM32L151R6T6A operates at up to 32 MHz in Run mode, consuming 185 µA/MHz (typical) at 3.3 V and 25°C. At full speed, this equates to approximately 5.92 mA total active current - verified in Table 18 of ST's DocID024330 Rev 5. Dynamic voltage scaling allows reduced core voltage at lower frequencies to further cut power in non-real-time tasks.

Does the STM32L151R6T6A support USB device functionality without external components?

Yes - it integrates a full-speed USB 2.0 device PHY and a dedicated 48 MHz PLL, eliminating the need for external crystal or transceiver. The USB interface supports CDC, HID, and MSC classes out-of-the-box using ST's USB library, and has been validated per USB-IF test specifications in production silicon (Section 3.16.4, DocID024330).

How many I/O pins are 5V tolerant, and what is the absolute maximum rating?

All 73 GPIOs are 5V tolerant when VDD is powered (1.65–3.6 V), with absolute maximum input voltage of 5.5 V on any I/O pin - confirmed in Section 6.3.13 (I/O port characteristics) and Table 43 of the datasheet. This enables direct interfacing with 5V logic, RS-232 level shifters, and industrial sensors without external buffers.

Is the 4 KB EEPROM truly standalone, and what endurance does it offer?

Yes - the 4 KB EEPROM is implemented as a separate memory block with built-in ECC, independent of Flash. It guarantees 100,000 write/erase cycles and 20-year data retention at 55°C (Table 37, DocID024330), and supports byte/word programming - making it suitable for storing calibration data, device IDs, and usage logs in field-deployed equipment.