Measured using the EEMBC ULPBench tests for low-power microcontrollers, STM32L4 devices achieve 176.70 ULPMark-CP, without the help of a buck converter that adds external components such as a coil and capacitor. The EEMBC CoreMark score of 273.55 at 80 MHz shows that the STM32L4 series delivers a combination of high peak performance and energy efficiency.
The performance and efficiency advantages come from smart architectural features such as independently adjustable peripheral supply voltages and a programmable multi-speed internal clock, as well as Batch Acquisition Mode (BAM) and ST’s Adaptive Real-Time Accelerator (ART Accelerator). Multiple power-management modes, including ultra-low-power 8 nA shutdown, help maximise energy savings.
Designers can now access these advantages in six added STM32L4 lines that offer economy, a range of application-targeted features, and extra package choices. The STM32L471 combines up to 1 MB Flash with rich analogue and audio features for projects that require no LCD controller or USB connectivity. The STM32L475 has a USB OTG Full Speed controller, and both devices have multiple timers, clock sources, and communication interfaces including CAN, SDMMC, USART, SPI, and I²C. The analogue peripherals include 12-bit ADCs with 5 MSPS capability and power-saving modes, as well as two 12-bit DACs, two op-amps with built-in Programmable-Gain Amplifier (PGA), and two ultra-low-power comparators.
The STM32L432 and STM32L433 bring 100DMIPS ARM Cortex-M4 core performance to lightweight applications that require up to 256 kB Flash. Analogue and audio features combine with a crystal-less USB controller in the STM32L432. The STM32L433 additionally features an LCD controller. Both lines support extra package options, from 7 x 7 mm UFBGA100 to 3.14 x 3.13 mm WLCSP49, including the small-footprint UFQPN32 for customers without WLCSP-assembly capability.
STM32L442 and STM32L443 lines offer designers the same feature sets and flexibility as the STM32L432/433, with the addition of a cryptographic accelerator in each device.