When an IoT customer, impressed with our EFR32BG22 (BG22) performance, wanted to achieve the best possible battery life for their application, Silicon Labs accepted the challenge. Field Applications Engineer, Marius Turculet, began testing and found that BG22 could achieve 30 to 40 percent of power savings when combined with our EFP01 Energy Friendly PMIC family. Click here to watch the entire presentation and register now for future Tech Talks. Highlights from Marius' session are below.
EFR32BG22 and EFP01 Used Together
BG22 is our most energy-friendly wireless system-on-chip (SoC). Equipped with an Arm® Cortex®-M33 core, BG22 SoCs achieve extremely low power levels while in an operational sleep state down to 1.4 µA.
BG22 is capable of dynamic voltage scaling (DVS), a power management technique used to make voltage changes "on-the-fly." DVS is an important power savings feature because the relationship between dynamic power consumption, operating frequency and operating voltage means that voltage scaling can significantly reduce power consumption.
Another BG22 feature is that it can disable the internal digital LDO. By disabling the LDO and replacing input from a buck converter, you can achieve 85-90 percent power transfer efficiency. A buck converter requires only a fraction of the LDO's current to supply the DECOUPLE node. Thus, by using an external dc/dc converter in the buck topology, you can achieve an efficiency of 30 to 40 percent over what the digital LDO would need to deliver the same energy to the digital logic.
Our EFP01 enables using an external dc/dc buck converter in place of the internal digital LDO. EFP01 is a flexible, highly efficient, multi-output power management IC dedicated for EFM32 MCUs and EFR32 wireless devices. It supports a broad range of input voltages (0.8 to 5.5 V), allowing developers to use different battery types and chemistries for optimal efficiency.
Used together, BG22 and EFP01 can achieve an even lower power consumption rate than using BG22 as a standalone device. This setup takes advantage of the following device features:
For testing, the EFP0108 PMIC variant was setup with the following parameters:
The BG22 features the following parameters:
All measurements (voltage, current, power) were taken at the VIN input node, representing a power supply input or a battery supply in real-world systems. Additionally, the setup supplies all the necessary BG22 rails and EFP01 current consumption while also accounting for all efficiencies in both dc/dc converters.
Software for the EFP0108 device was configured using the Simplicity Studio EFP Configuration Tool. BG22 software was configured using an SoC empty project, a software example project delivered with the Bluetooth Low Energy (LE) software stack and Gecko SDK (2.7.6).
Tests were conducted in both advertising and connection modes, with similar parameters for each test case. In both cases, the transition between modes were managed on-the-fly by the Bluetooth LE stack and the BG22 energy management unit (EMU).
Tests were run on a series of different designs, in the following order:
Each testing stage revealed increasing power consumption improvements, resulting in power and current consumption savings of 30 to 40 percent when using BG22 with a PMIC and employing DVS on a DECOUPLE power net.
The results of these tests demonstrate that BG22 can achieve even greater power savings than its best-in-class standards when combined with our energy-friendly EFP01 PMIC devices. To learn more about our BG22 and EFP01 devices' power-saving capabilities, contact your Silicon Labs sales representative.