STMicroelectronics STM32L151CBT6

Overview

STM32L151CBT6 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 STM32L151CBT6 datasheet, STM32L151CBT6 pinout, STM32L151CBT6 application, or STM32L151CBT6 equivalent, key selection criteria include verified 0.28 µA Standby current, USB 2.0 full-speed interface with internal 48 MHz PLL, LCD driver exclusion (per device variant), and LQFP48 package compatibility with 73 5V-tolerant I/Os.

Technical Context

The STM32L151CBT6 integrates a Cortex-M3 core running up to 32 MHz with MPU, dynamic voltage scaling across six low-power modes (Run, Sleep, Low-power Run, Stop, Standby), and dedicated power management including BOR with five thresholds, PVD, and ultra-low-leakage I/Os (<10 nA). Its clock system combines HSE (1–24 MHz), LSE (32.768 kHz RTC), 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 functional down to 1.8 V supply. The 7-channel DMA controller supports concurrent transfers for ADC, DAC, USB, and communication peripherals without CPU intervention.

Key Specifications

Pinout & Package

LQFP48 (7 × 7 mm, 0.5 mm pitch) package with exposed pad for thermal dissipation; 48-pin quad flat lead frame optimized for low-inductance routing and EMI resilience in battery-operated systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with STM32L151CBT6, STM32L431CBT6 trades EEPROM and USB for higher compute density and cryptographic features, while EFM32PG12B500F1024GL125 offers deeper sleep and larger memory but omits USB - making STM32L151CBT6 optimal for cost-sensitive, USB-enabled, EEPROM-reliant metering designs.

Availability

STM32L151CBT6 is available at Aetrix Electronics and suitable for portable medical sensors, smart utility meters, industrial data loggers, and wireless sensor nodes requiring stable component supply across extended product lifecycles.

Supply support for STM32L151CBT6 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 demanding multi-year battery life, robust memory integrity, and mixed-signal integration - specifically engineered for metering, wearables, and industrial IoT endpoints.

FAQ

Does STM32L151CBT6 include an integrated LCD controller?

No. The STM32L151CBT6 excludes the LCD driver present in STM32L152 variants. This is confirmed in Section 2.1 ("Device overview") and Table 1 of the datasheet, which explicitly states "LCD Driver (except STM32L151x6/8/B-A devices)". Designers requiring segment LCD support must select STM32L152CBT6 or add an external controller.

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

At 1.8 V, the STM32L151CBT6 supports up to 16 MHz CPU frequency, as defined in Table 4 ("CPU frequency range depending on dynamic voltage scaling") and validated in Section 6.3.1. Operation above 16 MHz requires ≥2.0 V supply to meet timing margins per electrical characteristics.

How many I/O pins support capacitive sensing functionality?

Up to 20 dedicated channels support capacitive sensing, as specified in the "Features" section and Section 3.14 ("Touch sensing"). These map to GPIOs across ports A, B, C, and D - each configurable as touchkey, linear slider, or rotary wheel inputs with built-in charge-transfer measurement.

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

Yes, the HSI (High-Speed Internal) RC oscillator is factory-trimmed to ±1% accuracy across temperature and voltage, as documented in Section 3.4 ("Clock management") and Table 31. This enables reliable USB clock generation via PLL without external crystal, reducing BOM cost and board space.