STM32 Kit with high accuracy crystal

[IAhma.1]

Hi,

I am looking for an STM based MCU/kit with high accuracy crystal oscillator with possible option to fine tune the frequency. I want to use it for some high accuracy time reference. Looking for suggestion please.

- ijaz

[TDK]

Crystals are high accuracy by their very nature. As long as it uses one, it should be accurate to tens of ppm. What accuracy do you need?

The STM32H7 series can use fractional PLL loop to further tune the clock.

This uses a crystal (NX3225GD-8MHz-EXS00A-CG04874) accurate to ±20 ppm. Probably can't get much better with ST boards.

https://www.st.com/en/evaluation-tools/nucleo-h743zi.html

[IAhma.1]

Actually I need a board with stable oscillator from 0-degree to 50-degree temperature. I want to measure accurate signal time over 12hrz. I heard that normal crystal oscillators have some variations over temperature. A board I know is STM32WB which i guess provide crystal tuning.

[TDK]

Everything has variation over temperature. There is no perfect clock source. You haven’t answered what amount of error is acceptable to you. “No error�? is not an option.

[Uwe Bonnes]

Define "hifg accuracy" and "fine tune range"

[Tesla DeLorean]

Cause some of us have higher standards than others..

[IAhma.1]

I want to measure accurate signal time over 12hrz. I heard that normal crystal oscillators have some variations over temperature.

[Tesla DeLorean]

Can't you just mount a VCTCXO ? How hard can that be? Wire it to a DAC with a LPF.

SiTime has a part you can trim via I2C

How about using a LEA-M8F, clocking the STM32 with the 30.72 MHz? GNSS locked that's good to 5ppb

The Murata module here claims to have a TCXO +/- 2ppm, near term probably a fraction of that.

https://www.st.com/en/evaluation-tools/b-l072z-lrwan1.html

[IAhma.1]

Actually I want to measure a signal time over 12hrz long via STm32 timer. for that purpose I need a reference board with stable XTL frequency.