STM32L151CBU6 - 32MHz Cortex-M3 128KB Flash Ultra-Low-Power MCU | STMicroelectronics
N.º de pieza: STM32L151CBU6 ✓ ActivoSTM32L151CBU6 Descripción general
An ultra-low-power microcontroller is a type of embedded processor engineered to minimise energy consumption during both active operation and deep sleep. This class of device sits inside the broader hierarchy of microcontroller -> embedded processor -> semiconductor, and it differs from general-purpose Cortex-M parts by adding low-power modes, RTC wake-up capability, and analog peripherals designed for battery-operated equipment. The STM32L1 series specifically targets energy-harvesting, metering, sensor-hub, and connected-USB applications where average current draw matters more than raw compute.
Key differentiating features include the Cortex-M3 core with hardware multiplier, 128 KB Flash for firmware and data, 16 KB SRAM, 4 KB of EEPROM, and a rich peripheral set spanning USART, SPI, I2C, timers, ADC, DAC, USB, and an LCD controller. Because the analog conversion and USB blocks are on-chip, no external converter or transceiver is required for typical sensor-to-host designs.
Architecturally the part is built around a 32-bit Cortex-M3 pipeline with low-power sleep, low-power run, and stop modes, backed by a real-time clock with wake-up timers and external interrupts. The analog section provides a 12-bit successive-approximation ADC with multiple inputs plus a 12-bit DAC on one of the timer outputs, which lets a single device both acquire a sensor signal and generate an excitation or reference voltage without extra silicon.
Typical applications include USB-connected sensor and data-logger dongles, smart metering and energy-harvesting nodes, low-power LCD instruments such as thermostats and industrial panel meters, portable medical and wellness monitors with analog front ends, IoT gateway modules, and battery-powered industrial data-acquisition terminals.
When designing with this device, budget the supply rail carefully: the USB and analog blocks require headroom for their operating ranges, and decoupling capacitors should sit directly on the power pins. Keep analog signal routing away from the switching and USB return paths, and confirm the temperature grade and regulator topology against the manufacturer datasheet before committing to a production layout.
This page consolidates the device parameters, verified distributor availability, qualified drop-in alternatives in the same 48-pin UFQFPN footprint, and practical design notes that go beyond the manufacturer datasheet, giving design and sourcing engineers one reference for the STM32L151CBU6.
Alternativas directas para STM32L151CBU6 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con STM32L151CBU6 (mismo factor de forma y huella) — difiere en Package, Flash Memory, ADC, Maximum CPU Frequency, Product Type.
STM32L151CBU6A
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
STM32L152CBU6
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
STM32L151C8U6
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
STM32L152C8U6
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →STM32F103CBU6TR
✅ Sustitución directa ⚠️ Especificaciones sin verificarConsulte el precio
Ver hoja de datos →STM32L151CBU6 Valores máximos y características eléctricas
| Product Type | Ultra-low-power 32-bit microcontroller (MCU) |
| Core | ARM Cortex-M3 with hardware multiplier |
| Bit Width | 32-bit |
| Maximum CPU Frequency | 32 MHz |
| Flash Memory | 128 KB (128K x 8) |
| SRAM | 16 KB |
| EEPROM | 4 KB |
| Encapsulado | 48-UFQFPN (7x7 mm) |
| Recuento de pines | 48 pins |
| Tipo de montaje | Surface Mount |
| USB | USB device controller, full-speed capable |
| ADC | 12-bit ADC, multiple analog inputs |
| DAC | 12-bit DAC |
| LCD Controller | On-chip LCD controller and segment/segment driver |
| Programmable Communication Interfaces | USART, SPI, I2C |
| Datasheet Document | STM32L151CB datasheet (133 pages per datasheet aggregator) |
Guía de configuración de pines de STM32L151CBU6 48-ufqfpn (7x7 mm)
Configuración de pines para STM32L151CBU6 (encapsulado 48-ufqfpn (7x7 mm)). Este CI digital incluye GPIO, interfaces de comunicación (UART, SPI, I2C) y pines de alimentación. Consulte la hoja de datos del fabricante para conocer las funciones alternativas de los pines y las opciones de configuración. Esencial para el diseño de sistemas embebidos y el diseño de PCB.
No hay datos detallados de patillaje disponibles para STM32L151CBU6.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
STM32L151CBU6 es adecuado para 6 aplicacións: USB-Connected Sensor and Data-Logger Dongle, Smart Metering and Energy-Harvesting Node, Low-Power LCD Panel Meter and Thermostat, Portable Medical and Wellness Monitor, Industrial IoT Gateway and Wireless Sensor Node, Battery-Powered Data Acquisition Terminal.
USB-Connected Sensor and Data-Logger Dongle
The STM32L151CBU6 suits compact USB dongles because it places a 32 MHz Cortex-M3 core, 128 KB of Flash and a full-speed USB device controller on a single 7x7 mm 48-pin UFQFPN, so no external USB transceiver or second MCU is required. A typical design samples a sensor through the 12-bit ADC, stores buffered records in the 16 KB of SRAM, and enumerates as a USB mass-storage or CDC device. Compared with a discrete USB bridge plus MCU, this consolidation cuts board area dramatically and reduces standby current because the unused analog and digital blocks can be left unpowered between transfers.
Recomendado
Smart Metering and Energy-Harvesting Node
Energy-harvesting and metering designs are constrained by average current draw, and the STM32L151CBU6 answers this with low-power run, sleep and stop modes plus a real-time clock with wake-up timers. The 12-bit ADC acquires the rectified sensor or coil signal while the 12-bit DAC can generate a calibration reference, avoiding the always-on current of external converters. With 128 KB of Flash for protocol stacks and 16 KB of SRAM for rolling buffers, the part supports LoRa-class or sub-GHz metering nodes, and its 48-pin UFQFPN footprint keeps the module under 10 mm on a side.
Recomendado
Low-Power LCD Panel Meter and Thermostat
The STM32L151CBU6 integrates an LCD controller with segment drive capability, so a panel meter or thermostat needs no external display driver. The 12-bit ADC handles the temperature or pressure input, the 12-bit DAC can bias the sensor or drive a reference channel, and the 32 MHz Cortex-M3 runs the display refresh, keypad scan, and control loop from a single part with 128 KB of Flash for UI code. Because the display and analog blocks can be sequenced independently in low-power modes, the module can show a live reading while keeping average current in the microampere class.
Recomendado
Portable Medical and Wellness Monitor
Battery-operated wellness and portable diagnostic devices need low noise and low power, and the STM32L151CBU6 combines a 12-bit ADC with a 12-bit DAC plus a low-power Cortex-M3 core in a 7x7 mm package. Signal acquisition from a bridge or biopotential front end, baseline drift correction, and on-board data logging all run from the 128 KB of Flash and 16 KB of SRAM, while the stop mode and RTC allow the device to sleep between measurement bursts. The small footprint supports integration into wristbands and handheld units where board area and standby current are the primary constraints.
Recomendado
Industrial IoT Gateway and Wireless Sensor Node
Industrial IoT nodes typically act as concentrators for multiple low-speed sensors, and the STM32L151CBU6 fits this role with USART, SPI and I2C interfaces alongside 128 KB of Flash and 16 KB of SRAM. It can host a local protocol stack, aggregate readings from external sensors, and drive an LCD or LED status indicator, while the low-power modes let it operate from a small energy budget on industrial bus nodes. The 48-pin UFQFPN footprint also enables a compact radio module design where a co-packaged wireless device needs a local MCU for framing and low-power duty cycling.
Recomendado
Battery-Powered Data Acquisition Terminal
Field data loggers for environmental or process monitoring benefit from the STM32L151CBU6's combination of 128 KB of Flash for buffered records, 16 KB of SRAM for working storage, and a 12-bit ADC for multi-channel analog capture. The on-chip DAC generates excitation or offset voltages for ratiometric sensor interfaces, removing an external source and its associated supply current. Low-power stop mode with RTC wake-up lets a unit record at scheduled intervals and survive long unattended deployments, while the USB device port permits direct recharging and data export without adding a separate interface chip.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para STM32L151CBU6 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | STM32L151CBU6A | STM32L152CBU6 | STM32L151C8U6 | STM32L152C8U6 | STM32F103CBU6TR |
|---|---|---|---|---|---|---|
| Package | 48-UFQFPN (7x7 mm) | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same | 48-UFQFPN (7x7 mm) - same footprint |
| Brand | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics | STMicroelectronics |
| Core | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit | ARM Cortex-M3, 32-bit |
| Maximum CPU Frequency | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 32 MHz | 72 MHz (+125%) |
| Flash Memory | 128 KB | 128 KB | 128 KB | 64 KB (-50%) | 64 KB (-50%) | 128 KB |
| SRAM | 16 KB | 16 KB | 16 KB | 16 KB | 16 KB | 20 KB (+25%) |
| EEPROM | 4 KB | 4 KB | 4 KB | 2 KB (-50%) | 2 KB (-50%) | None on-die |
| USB Device Controller | Yes | Yes | Yes | Yes | Yes | No |
| On-chip DAC | 12-bit DAC | 12-bit DAC | 12-bit DAC | 12-bit DAC | 12-bit DAC | No (12-bit ADC only) |
| Hardware Cryptography | Not specified | Not specified | Yes (crypto accelerator) | Not specified | Yes (crypto accelerator) | Not specified |
| LCD Controller | Yes | Yes | Yes | Yes | Yes | No |
| Low-Power Positioning | Ultra-low-power STM32L1 series | Ultra-low-power STM32L1 series | Ultra-low-power STM32L1 series | Ultra-low-power STM32L1 series | Ultra-low-power STM32L1 series | General-purpose STM32F1 series |
Diferenciadores clave
- Closer functional match than any general-purpose STM32F part (frente a STM32F103CBU6TR)
- Drop-in family upgrade with hardware cryptography and no memory penalty (frente a STM32L152CBU6)
- Identical order code alternative already in distribution (frente a STM32L151CBU6A)
- Memory headroom for code-heavy firmware at the same pin count (frente a STM32L151C8U6)
Notas de diseño
The UFQFPN48 footprint requires a dedicated exposed-pad land pattern connected to ground, not a generic 48-pin QFN pad set. Follow the recommended PCB land geometry in the STM32L151CB datasheet package information section, including the thermal-via array under the exposed pad, and pour ground copper on the same layer to keep junction temperature low. Keep the 48-pin routing free of vias where possible so that assembly and X-ray inspection remain simple.
The analog, USB and digital sections all draw from the device supply rails, so place the bulk and high-frequency decoupling capacitors directly at the corresponding power pins rather than at the connector. A common arrangement is a larger bulk capacitor near the supply entry plus a 100 nF ceramic at each supply pin, with the regulator placed close enough that the supply trace is short and wide. Verify the minimum supply voltage required by the USB and ADC blocks in the electrical characteristics table before selecting the system regulator.
Route analog inputs away from the USB data lines, the ADC reference pins, and the switching node of any nearby regulator. The 12-bit ADC and 12-bit DAC on this part are sensitive to supply and ground bounce, so provide a clean return path for analog ground and keep the USB transceiver return current out of the analog ground region. If a reference voltage is used, treat it as a sensitive analog net with its own bypass capacitor close to the pin.
When substituting a lower-memory variant such as the STM32L151C8U6 for the STM32L151CBU6, review the linker script and boot configuration because Flash drops from 128 KB to 64 KB, and check the EEPROM size difference as well. Likewise, moving to the STM32F103CBU6TR changes the clock tree from 32 MHz to 72 MHz and removes the USB, DAC and LCD peripherals, so any firmware or board change must be re-validated rather than assumed drop-in.
Estimated: with the exposed pad bonded to a 400 mm2 ground pour on a four-layer board, the junction-to-ambient rise is modest at typical regulator and I/O loads, but self-heating still matters in sealed enclosures. Treat the thermal figures in the datasheet as the basis for enclosure design, verify with a thermocouple on the exposed pad during bring-up, and keep the keep-out area around the device free of tall components that would obstruct the airflow path in a sealed instrument.
Información de cumplimiento
Compliance status is reported by distributors on part comparison pages but no explicit RoHS, REACH, lead-free or halogen-free statement was captured verbatim, so each field is left unknown rather than assumed. The device is an industrial/consumer microcontroller, so AEC-Q100 automotive qualification is not applicable unless an automotive-grade order code is selected.