Product overview
Description
The X-CUBE-CLKTRIM Expansion Package illustrates the trimming of an HSE crystal oscillator to reach the high-accuracy frequency required by RF applications. The STM32WB Series microcontrollers support low-power RF standards such as Bluetooth® Low Energy (±50 ppm minimum HSE clock accuracy) and IEEE 802.15.4 (±40 ppm minimum HSE clock accuracy).The STM32WL Series microcontrollers support sub-GHz RF standards such as LoRaWAN® and other low-power wide area networks (LPWAN). For these standards, the highest the HSE clock accuracy, the best the RF performance.
The frequencies of STM32 Wireless MCUs HSE oscillators can be tuned by means of values saved in dedicated registers. This features saves the extra cost of additional external capacitors and enables the compensation for frequency variations due to production, crystal, and PCB design.
The X-CUBE-CLKTRIM Expansion Package and associated application note (AN5042, AN5515) propose three different trimming procedures (manual, automatic, and with STM32CubeMonitor-RF (STM32CubeMonRF)) for the once-for-all storage of the right trimming parameters in OTP bytes. Each proposes two configurations: the trimming procedure itself and an implementation example of oscillator clock initialization in applications (loading of the trimming parameters in the according registers).
The HSE trimming manual procedure requires the user to use buttons to trim the RF clock frequency, which is output on a pin and can be monitored with a precision frequency meter. The HSE trimming automatic procedure consists in providing a precision clock reference to the STM32 so that it can trim its RF clock frequency (HSE) automatically. The HSE trimming procedure with STM32CubeMonitor-RF is similar to the manual one but uses STM32CubeMonitor-RF scripts instead of buttons.
For HSE trimming, it is not mandatory to trim each board in a production chain. A procedure is given for this purpose in the Precise HSE frequency trimming using STM32 wireless MCUs application note (AN5042).
X-CUBE-CLKTRIM firmware is built on the HAL drivers and runs on the Nucleo boards of the STM32 Wireless MCUs.
-
All features
- STM32 Wireless MCUs high-speed external (HSE) crystal oscillator trimming allowing best RF performance for Bluetooth® Low Energy, IEEE 802.15.4, LoRaWAN® and LPWAN wireless applications
- Trimming parameters can be stored in user OTP Flash area
- Trimming in production procedure suggestion
Get Software
You might also like...
Featured Videos
Follow issues and share solutions on Github for STM32Cube MCU packages. Integrate your own software components in a STM32Cube Expansion for STM32CubeMX and STM32CubeIDE tools, thanks to the new STM32PackCreator utility
STM32CubeMX is part of the STM32Cube initiative designed to simplify and accelerate the development of applications for STM32 microcontrollers. STM32CubeMX offers the possibility to generate C projects using embedded software offers packages like CMSIS-Pack compliant software packs. Starting with the 6.0.0 revision, STM32CubeMX is delivered with STM32PackCreator, an STM32 pack creation graphical companion tool, whose main purpose is the creation of software packs.
MadeForSTM32™ is a new quality label delivered by ST, which is granted after an evaluation process. It helps engineers identify third party solutions with the highest level of integration and quality for the STM32 microcontrollers' ecosystem. MadeForSTM32™ is offered to members of the ST Partner Program who want to go one step further in our collaboration, with the overall objective of contributing to a high-quality STM32 ecosystem.
