STMicroelectronics STM32L151R8H6TR

Overview

STM32L151R8H6TR 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 loggers, and smart utility meters requiring sub-µA standby operation.

For engineers reviewing the STM32L151R8H6TR datasheet, STM32L151R8H6TR pinout, STM32L151R8H6TR application, or STM32L151R8H6TR equivalent, key selection criteria include verified ultra-low-power mode current (0.28 µA Standby), USB 2.0 full-speed support with internal 48 MHz PLL, LCD driver exclusion per device variant, and LQFP64 package compatibility with 73 5V-tolerant I/Os.

Technical Context

The STM32L151R8H6TR integrates a Cortex-M3 core operating up to 32 MHz with MPU, dynamic voltage scaling, and five low-power modes (Run, Sleep, Low-power Run, Stop, Standby) - each with distinct peripheral availability and wakeup latency (e.g., <8 µs from Stop). Its clock system combines 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 12-bit ADC with programmable sampling time across 24 channels - all functional down to 1.8 V supply. The 7-channel DMA controller supports memory-to-peripheral transfers without CPU intervention.

Key Specifications

Pinout & Package

LQFP64 package: 64-pin low-profile quad flat package, 10 × 10 mm body, 0.5 mm pitch, exposed pad optional for thermal enhancement. Pinout validated per STMicroelectronics DocID024330 Rev 5, Section 4 (Pin descriptions) and Table 9 (pin definitions).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L151R8H6TR, STM32L431RCI6 trades EEPROM and ultra-low standby for Cortex-M4F compute density, while EFM32PG12B500F1024GL125 achieves deeper sleep at the cost of USB integration and analog peripheral richness - making STM32L151R8H6TR optimal for USB-connected, EEPROM-dependent, battery-constrained designs.

Availability

STM32L151R8H6TR is available at Aetrix Electronics and suitable for wearable health monitors, smart utility meters, and portable data loggers requiring stable component supply across multi-year production cycles.

Supply support for STM32L151R8H6TR 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 - optimized for battery-operated devices demanding sub-µA sleep currents, integrated analog peripherals, and robust memory reliability in harsh environments.

FAQ

Does STM32L151R8H6TR include an integrated LCD controller?

No. The STM32L151R8H6TR belongs to the STM32L151x6/8/B-A family, which explicitly excludes the LCD controller - unlike the STM32L152x6/8/B-A variants. This omission reduces die size and power consumption, making it ideal for non-display applications such as sensor nodes and metering endpoints where LCD drive is unnecessary.

What is the maximum allowed crystal frequency for the HSE oscillator?

The HSE oscillator supports external crystals from 1 MHz to 24 MHz, as specified in Section 6.3.6 of the official datasheet (DocID024330 Rev 5). Operation above 24 MHz violates absolute maximum ratings and may cause startup failure or timing instability in USB and system clocks derived from the PLL.

How many I/O pins support 5V tolerance, and which ports are included?

73 I/O pins are 5V tolerant, covering all pins of GPIO ports A, B, C, D, and E except for those dedicated to USB (PA11/PA12), OSC (PH0/PH1 on other packages), and JTAG/SWD (PA13/PA14). This tolerance is confirmed in Section 2.1 and Table 2 of the datasheet and allows direct interfacing with 5V logic without level shifters.

Is the internal 16 MHz RC oscillator factory-trimmed, and what is its accuracy?

Yes, the HSI (High-Speed Internal) 16 MHz RC oscillator is factory-trimmed to ±1% accuracy across temperature and voltage ranges, as documented in Section 6.3.7 (Table 31) of the datasheet. This specification enables reliable USB clock generation via PLL without requiring an external crystal in cost-sensitive designs.