STM32 Low Power Series
The STM32 Low Power series features a powerful yet energy-efficient family of devices based on the ARM Cortex M0+, M4 and M33. Advanced power management and availability of several power modes enable the construction of battery-powered devices capable of operating for months or even years without a need for recharge, e.g. STM32L4 chips can go as low as down to 0.34uA (micro Amper) of power consumption in their lowest power mode. Still, the versatility of the series brings chips with flash memory up to 2MB for resource-demanding applications.
A short review of the MCUs and their features is listed in table 1. Note each row in the table represents a family of devices, and a particular configuration depends on the exact MCU model. Thus, developers, when looking for specific features, in particular energy efficiency and power saving options, should refer to the manufacturer's specification and list of currently available devices [1].
Table 1: STM32 Ultra Low Power series
| Series: | CPU (Core/Cores) | RAM (*-not all chips/versions) | Flash / EEPROM | Interfaces (*-not all chips/versions) | Voltage (*-not all chips/versions) | Other features (*-not all chips/versions) |
|---|---|---|---|---|---|---|
| SMT32L0 | Cortex M0@32MHz | up to 20kB | 128kB/192kB flash 512B/6K EEPROM | 12-bit ADC (1.14Msps) USART USART SPI I2C LP UART PVD (Programmable Voltage Detector)* USB 2.0 FS* 2×12-bit DAC* | Dynamic Voltage Scaling Down to 1.8V* Down to 1.65V* | Dynamic Voltage Scaling 5 Clock Sources Advanced RTC with Calibration 16-bit Timers Low Power Timers 2x Watchdog DMA AES-128 Temperature Sensor* Segment LCD Driver (4×52/8×48)* Random Number Generator* Touch Sense* 2xUltra Low PPower Comparators |
| STM32L4 | Cortex-M4@80MHz (DSP+FPU) | 40kB to 320kB | 64kB to 1024kB | USART UART SPI I2C Quad-SPI 1/2 SAI+Audio PLL* SWP (Bank Swap Pin) 1/2 CAN* 1/2 12-bit DAC* FSMC 4/8 Sigma Delta Interfaces* 1-3 12-bit ADC (5Msps) with 16-bit Over-sampling USB 2.0 OTG* USD 2.0 DEV* | 1.71V to 3.6V | ART Accelerator Chrom-ART Graphic Accelerator 16 and 32-bit Timers Temperature Sensor Vbat Battery Voltage Mode Unique ID Capacitive Touch Sensing Hardware Crypto AES-128/256* Hardware SHA-256* 1/2 Op Amps |
| STM32L4+ | Cortex-M4@120MHz (DSP+FPU) | 320/640kB | 512kB to 2048kB | USART UART SPI I2C 2xQuad-SPI SAI+Audio PLL* CAN Camera Interface 2×12-bit DAC* SDIO FSMC 4/8 Sigma Delta Interfaces* 1/3 12-bit ADC (5Msps) with 16-bit Over-sampling USB 2.0 OTG TFT Display Interface* MIPI-DSI* | 1.71V to 3.6V | 2xWatchdog |
| STM32L5 | Cortex M33@110MHz (TrustZone+DSP+FPU) | 256kB | 256kB to 512kB | USART UART SPI I2C Octo-SPI FMC* SAI+Audio PLL* CAN-FD 2x 4ch Sigma Delta Interfaces* 2×12-bit DAC* 2×12-bit ADC (5 Msps) with 16-bit Over-sampling USB 2.0 DEV USB 2.0 HS USB-C Power Delivery | 1.71V to 3.6V | 16 and 32-bit Timers ART Accelerator Hardware Accelerated SHA Random Number Generator Temperature Sensor Vbat Battery Voltage Mode Unique ID Capacitive Touch Sensing 2xOp Amps 2xComparators Hardware Crypto AES, PKA, OTFDEC 128/256-bit* |
| STM32U5 | Cortex M33@160MHz (TrustZone+DSP+FPU) | 274kB/786kB/2514kB Dual bank flash* | 128kB to 4096kB | SDIO 1/2 Octo-SPI* Hexadeca-SPI* FSMC* HSPI* USB 2.0 FS* USB 2.0 HS* USB-C Power Delivery* TFT-LCI and DSI Interfaces* 2×12-bit DAC* 1/2 14-bit ADC (2 Msps)* 1×12-bit ADC (2Msps) USART UART LPUART SPI I2C CAN-FD ADF* Camera* MDF* SAI* SD/MMC* | 1.71V to 3.6V | 16 and 32-bit Timers 2xAdvanced Motor Control Timers 4xUltra Low Power Timers Neo-Chrom GPU* Chrom-ART Graphic Accelerator* Hardware Crypto AES 128/256, PKA, OTFDEC 128/256-bit* 2xWatchdog RTC 2xOp Amps 2xComparators Hardware Accelerated SHA and MD5 Random Number Generator Capacitive Touch Sensing LPDMA Temperature Sensor Unique ID |
