LPC MicrocontrollersのトピックRe: PLL startup time

PLL startup time

alexeyborisenko — Wed, 07 Feb 2018 13:39:56 GMT

How much time will be enogh for PLL to lock?

i.e. timeout after which i can assume failure if it not locked yet.

LPC812.

Re: PLL startup time

kerryzhou — Fri, 09 Feb 2018 08:05:20 GMT

Hi Alexey,

From the LPC812 datasheet, you can get this information:

Wish it helps you!

Have a great day,
Kerry

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Re: PLL startup time

alexeyborisenko — Fri, 09 Feb 2018 11:58:17 GMT

Thanks, Kerry, but I'm confused by word "nominally" there. It usually means that actual value may be more or less than nominal within some margins that must be also specified somewhere, e.g. 100us+-50% means 100us nominally and upper limit will be 150 us.

I need to know that upper limit.

Re: PLL startup time

kerryzhou — Sun, 11 Feb 2018 08:28:55 GMT

Hi Alexey,

Thank you for the updated information.

100us should be the typical data, and the datasheet don't have the precise min and max data, we also don't have it, normally we use while to wait the PLL lock.

If you want to use it, maybe you can refer to this data, you can use a little larger data as the compare time, and test some chips on your side, if the normal chip have no problem with that data, then you may use it. This is just a recommend thought, if you have interest, you can try it.

Have a great day,
Kerry