STMicroelectronics STM32L151RBT6

Overview

STM32L151RBT6 from STMicroelectronics is an ultra-low-power 32-bit ARM® Cortex®-M3 microcontroller featuring 128 KB Flash, 16 KB SRAM, 4 KB EEPROM with ECC, 12-bit ADC (1 Msps, 24 channels), and dual 12-bit DACs. It operates from 1.65–3.6 V, achieves 0.57 µA Stop mode current, and supports USB 2.0, three USARTs, two SPIs, and two I²Cs - deployed in battery-powered medical sensors and portable industrial data loggers.

For engineers reviewing the STM32L151RBT6 datasheet, STM32L151RBT6 pinout, STM32L151RBT6 application, or STM32L151RBT6 equivalent, key selection criteria include ultra-low-power mode timing (e.g., <8 µs wakeup), integrated EEPROM endurance (100k cycles), USB 2.0 full-speed compliance, LCD driver exclusion (confirmed for R-series), and 73 I/Os with 5V tolerance.

Technical Context

The STM32L151RBT6 implements dynamic voltage scaling across six low-power modes (Run, Sleep, Low-power Run/Sleep, Stop, Standby), with dedicated power domains for analog peripherals and real-time clock backup. Its Cortex-M3 core runs up to 32 MHz with MPU and 1.25 DMIPS/MHz performance, supported by a multi-source clock system including HSE (1–24 MHz), LSE (32.768 kHz), HSI (16 MHz ±1%), and MSI (65 kHz–4.2 MHz).

Analog subsystem integration includes two ultra-low-power comparators with window mode and wake-up capability, temperature sensor, internal VREFINT, and independent 12-bit ADC/DAC channels - all functional down to 1.8 V supply. The USB interface uses an internal 48 MHz PLL and requires no external crystal for full-speed operation.

Key Specifications

Pinout & Package

LQFP64 (10 × 10 mm, 0.5 mm pitch) package with exposed thermal pad; 64-pin quad flat configuration optimized for thermal dissipation and PCB routing density in space-constrained designs.

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 STM32L071RBT6, the STM32L151RBT6 adds true EEPROM and USB but consumes more active current; versus STM32L431RBT6, it trades peak performance and FPU for significantly lower Stop/Standby currents and proven 10+ year battery operation.

Availability

STM32L151RBT6 is available at Aetrix Electronics and suitable for portable medical sensors, smart utility meters, industrial wireless nodes, and asset tracking beacons requiring stable component supply across multi-year production cycles.

Supply support for STM32L151RBT6 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 demanding extended battery life, robust memory integrity, and rich analog integration - specifically engineered for metering, wearable health, and industrial IoT endpoints.

FAQ

Does STM32L151RBT6 include an integrated LCD controller?

No. The STM32L151RBT6 excludes the LCD controller present in STM32L152 variants. This is explicitly confirmed in Section 2.1 ("Device overview") and Table 2 of the datasheet, which lists "LCD" as supported only for STM32L152xx devices. The RBT6 variant retains all other analog and timing peripherals but omits the segment driver and step-up converter.

What is the maximum operating frequency with guaranteed timing at 1.8 V supply?

At 1.8 V, the STM32L151RBT6 supports a maximum CPU frequency of 16 MHz, as defined in Table 4 ("CPU frequency range depending on dynamic voltage scaling") and verified in Section 6.3.1. Operating above this frequency risks timing violations in Flash access and peripheral synchronization under low-voltage conditions.

How many I/O pins support 5V tolerance, and are they configurable per-pin?

All 73 GPIOs on the STM32L151RBT6 are 5V tolerant when VDD is ≥2.0 V, as specified in Section 6.3.13 ("I/O port characteristics") and Table 42. Tolerance is inherent to the I/O structure and does not require software configuration - no register setting is needed to enable or disable 5V tolerance.

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

Yes, the HSI oscillator is factory-trimmed to ±1% accuracy at 25°C and maintains ±2% over the full –40°C to +85°C range, per Table 30 ("HSI oscillator characteristics"). This specification enables reliable USB clock derivation (via PLL) and eliminates the need for an external crystal in cost-sensitive, non-precision timing applications.