STMicroelectronics Combines STM32 MCU and LoRa Transceiver on One SoC

By Rich Nass

Executive Vice President

Embedded Computing Design

January 15, 2020


STMicroelectronics introduced what it claims is the industry's first LoRa system-on-chip (SoC). Previously, the LoRa device was a separate transceiver that connected to a microprocessor.

LoRa continues to pick up steam as the wide-area network of choice. We know its limitations, mostly the low bandwidth, but for certain applications, like remote environmental sensors, meters, trackers, and process controllers that help efficiently manage energy and resources, it more than fits the bill.

To that end, STMicroelectronics introduced what it claims is the industry’s first LoRa system-on-chip (SoC). Previously, the LoRa device was a separate transceiver that connected to a microprocessor. Now it’s all in the same die. The advantages are obvious—a simpler design, lower power, and higher performance.

The STM32WLE5 SoC combines a low-power STM32 microcontroller design with a LoRa-compliant radio. Specifically, it leverages the STM32L4 architecture, which features an Arm Cortex-M4 core with DSP extensions and adds low-power technologies including dynamic voltage scaling and ST’s adaptive real-time ART Accelerator for zero-wait execution from flash memory.

Flash options of 64, 128, and 256 kbytes let developers choose the optimal code and data storage density for the entire platform including the application and radio. Built-in cyber-security features include hardware public key accelerator (PKA), True Random Number Generator (TRNG), sector protection against read/write operation (PCROP), and support for state-of-the-art cryptographic algorithms including RSA.

Incorporating the company’s radio Power Management Architecture, the new part maximizes overall efficiency. In addition, ST’s LoRaWAN software for wireless network communications has passed all regional certifications for use worldwide, removing another hurdle.

The integrated radio based on Semtech SX126x IP offers dual high- and low-power transmitter modes that cover the entire global sub-1GHz unlicensed frequency range from 150 to 960 MHz, ensuring compatibility with LoRa networks in all territories. Sensitivity down to -148 dBm, and two embedded power amplifiers with up to 15 and 22 dBm maximum transmit power are available in the same package to maximize RF range. The STM32WLE5 is also capable of (G)FSK, (G)MSK, and BPSK modulation, which allows for varying alternative protocols including proprietary protocols.

A 10-year longevity commitment for industrial products like the STM32WLE5 ensures that the product can be designed in for a long time. It’s available in a 5- by 5-mm UFBGA73 package, and has been integrated into ST’s STM32 ecosystem, which includes STM32Cube software support.

Richard Nass’ key responsibilities include setting the direction for all aspects of OSM’s ECD portfolio, including digital, print, and live events. Previously, Nass was the Brand Director for Design News. Prior, he led the content team for UBM’s Medical Devices Group, and all custom properties and events. Nass has been in the engineering OEM industry for more than 30 years. In prior stints, he led the Content Team at EE Times,, and TechOnLine. Nass holds a BSEE degree from NJIT.

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