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msemegen
msemegen
Associate III
October 25, 2023
Solved

STM32WB HSE tune

  • October 25, 2023
  • 3 replies
  • 1474 views

Hi,

What error on HSE frequency is acceptable by STM32WB35? More than 1 kHz can disturb connection process (its interrupted or it's slow than usual on some phones) or can cause unexpected disconnection? 

Does this affect the range of the advertisement ?

Best,
msemegen

 

This topic has been closed for replies.
Best answer by TDK

Are you using 802.15.4? If so, then no.

Even if you're just using BLE, if it were my product, I wouldn't ship something that had 47 ppm off if the limit was ±50 ppm. Things will drift with time and temperature.

3 replies

TDK
TDK
October 26, 2023

Per the datasheet:

50 ppm for Bluetooth Low Energy, 40 ppm for 802.15.4 and when both Bluetooth Low Energy and 802.15.4 are used.

 

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msemegen
msemegenAuthor
Associate III
October 26, 2023

According to this calculator https://www.everythingrf.com/rf-calculators/ppm-to-hz-calculator currently we are at 57 ppm level (~18000 Hz). Using hse tune techniques we can lower it to 47 ppm (which is a little bit lower than maximum error). 47 ppm will be good enough?

TDK
TDKBest answer
October 26, 2023

Are you using 802.15.4? If so, then no.

Even if you're just using BLE, if it were my product, I wouldn't ship something that had 47 ppm off if the limit was ±50 ppm. Things will drift with time and temperature.

"If you feel a post has answered your question, please click ""Accept as Solution""."
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