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Associate
September 3, 2026
Question

STM32H723ZGT6 + LAN8742AI - > PHY CRYSTAL PART SELECTION GUIDEANCE

  • September 3, 2026
  • 3 replies
  • 39 views

Hi STM Team,

We are currently using the 25 MHz crystal configuration based on the NUCLEO-H723ZG reference design for our STM32H723 + LAN8742 Ethernet implementation.

The original/reference crystal used is:

NX2016SA 25 MHz – EXS00A-CS11321 (NDK)

  • Frequency: 25 MHz
  • Load capacitance (CL): 6 pF
  • ESR: 80 Ω
  • Reference design uses approximately 5.1/5.6 pF load capacitors.

However, the above crystal is currently not readily available in the market, so we evaluated the following alternatives:

  1. ECS-250-6-37-JTN-TR – 25 MHz, 6 pF, 80 Ω
  2. X2C025000DZ1H-U
  3. XRCGB25M000F1SBAR0

With the above replacement crystals, we are observing significant data loss during Ethernet communication through the LAN8742.

We have already tried the recommended/reference crystal configuration and compared the Ethernet behavior with the replacement crystals, but the issue is still observed with the alternate parts.

Could you please help us identify a suitable 25 MHz crystal for the STM32H723 + LAN8742 configuration, preferably a currently available part that is electrically compatible with the original NX2016SA EXS00A-CS11321?

Also, please advise if any load capacitor value, series resistor, drive-level, or other oscillator configuration needs to be changed when using an alternative crystal.

Your recommendation for a qualified/validated replacement part would help us proceed with the design.

Thanks.

 

 

3 replies

mƎALLEm
ST Technical Moderator
September 3, 2026

Hello ​@eswar18 and welcome to the ST community,

LAN8742 is not ST product. Did you ask Microchip that question in their community?:  https://forum.microchip.com/

To give better visibility on the answered topics, please click "Best answer" on the reply which solved your issue or answered your question.
eswar18Author
Associate
September 4, 2026

Hi ,
Since we follows NUCLEO-H723ZG schematics, We seek your guidance on this to solve the same at earliest.
 

eswar18Author
Associate
September 4, 2026
Hi Team,
Please find the attached clock configuration (internal) for my case. 
Case : Full-duplex in ethernet.
​​​​
We are seeing data loss even with the actual crystal part with full-duplex mode. Please review on the clock configurations and review the same.

​There was about to 20 hardware , same PCBA & same purchased lot components, there was some 10 units working without data loss on ethernet full-duplex & other units has dataloss with full-duplex mode.

Please confirm internal clock configurations are suitable for this or case condition ?