LPC MicrocontrollersのトピックLPC54102 Max Freq of External clock input

LPC54102 Max Freq of External clock input

kennethkong852 — Sat, 26 Jul 2025 06:49:12 GMT

Hello,

I am referencing to both the User Manual and the Datasheet of LPC5410x and noticed the following:

From (User Manual) UM10850:
For clock generation, it states that External clock input can be up to 24 MHz.

From Product datasheet:
It states that External clock input for clock frequencies of up to 25 MHz.

Can you please advise which statement is correct?

Regards,

Kenneth

Re: LPC54102 Max Freq of External clock input

Alice_Yang — Mon, 28 Jul 2025 03:48:35 GMT

Hello @kennethkong852

Datasheet is correct.

External clock input for clock frequencies of up to 25 MHz.

I will escalate the UM issue to DOC team.

Thanks for your sharing.

Alice

Re: LPC54102 Max Freq of External clock input

kennethkong852 — Tue, 29 Jul 2025 18:30:28 GMT

Hi Alice,

Thank you for the reply and information there!

When I use the Clocks Config Tool (accessed from SDK Builder), I noticed that for the Configurator would not allow me to type in 25 MHz for CLKIN input. It's limited to 24 MHz.

Please see attached photo for reference.

CLKIN values

BR,

Kenneth

Re: LPC54102 Max Freq of External clock input

Alice_Yang — Wed, 30 Jul 2025 10:22:44 GMT

Hello @kennethkong852

Thanks for your report.

This is a bug in the Clocks Config Tool. The issue arises because the new version of DS has changed the frequency from 24M to 25M. In old version DS, still 24MHZ.

I will report this bug to the Config Tool development team promptly.

For now, if you need to use 25MHZ, please configure it via code.

I apologize for the inconvenience this has caused you.

Alice