Electronics Weekly
BG22L (diagram right) devices are aimed at asset tracking tags and personal healthcare devices, and support Bluetooth 5.4 and Bluetooth Direction Finding.
Processing power comes from a 38.4MHz Arm Cortex-M33 processor with up to 352kbyte of flash and up to 24kbyte of ram in a 4 x 4mm QFN32 package.
Security acceleration is provided, as is a precision 32kHz RC oscillator to replace sleep crystals, and up to ten years of operation from a single coin cell battery is claimed by SiLabs.
BG24L devices (left) will have a Bluetooth 6.0 radio with Bluetooth Channel Sounding – the latter allowing sub-metre relative location for item-finding and physical access security.
They will have a 78MHz Cortex M33 processor, 768kbyte of flash and 96kbyte of ram in a 5 x 5mm QFN40 package.
“For AI and machine learning applications, the BG24L also includes Silicon Labs’ matrix vector processor accelerator [which] provides up to 8x faster inferencing using only 1/6th the power compared to performing the same calculations on the Cortex M,” said the company.” This makes BG24L an ideal platform for time-series data on IoT applications such as sensors and predictive maintenance.”
BG22L is SiLabs-speak for its ERF32BG22L processors, and similar for BG24L.
The ‘L’ at the end stands for ‘Lite’, according to SiLabs, which explained that L is added to MCUs that are optimised for a narrower application space.
BG22L and BG24L are pin-compatible with the company’s earlier BG22 and BG24 respectively.
What are the differences?
Silicon Labs told Electronics Weekly:
While BG22 and BG22L are pin-compatible, they belong to different families. Based on customer and market feedback from using BG22, BG22L was developed for applications where the focus is more on energy efficiency and RF performance, with minimal flash and ram requirements. This is particularly relevant for connectionless applications where the primary function is to send out beacons for advertising. Keeping that in mind, BG22L retains all the energy-efficient features of BG22 but with reduced flash and RAM to cater to this specific market. The maximum Flash/RAM on BG22 is 512kB/32kB, while on BG22L it is 352kB/24kB. In terms of security, BG22L offers Secure Vault Mid as BG22.
BG24 and BG24L are also pin-compatible, but they belong to different families. We identified a need for basic AI/ML applications where the device primarily analyses data from various sensors to predict device failure. This type of preventive maintenance and anomaly detection requires a SoC that focuses on these tasks with minimal resources. BG24L was designed with this in mind. The same applies to channel sounding applications, where the end application only needs a channel sounding reflector, and the initiator is in a different host SoC. For these applications, as a reflector, you don’t need extensive memory resources for ranging. BG24L has a hardware accelerator like BG24 and offers all the features of BG24 but with reduced flash and ram. The maximum Flash/RAM on BG24 is 1536kB/256kB, while on BG24L it is 768kB/96kB. Regarding security, BG24L does not offer the highest level of security that is supported on BG24, as it is not necessary for the applications BG24L is designed for. BG24L offers Secure Vault Mid.
Find:
the BG22L product page here
the BG24L product page here
