XTAL crystal for 5LP prototyping kit

KeLa_4479261 · ‎Mar 08, 2020

Greetings to All:

I am trying to reduce the ppm number on the 5LP. I have enabled the USB tab in the clock settings and have got a clock running at 1250ppm. I was hoping to attach an external crystal with some capacitors and use them to create a more accurate clock.

I was hoping to use a watch crystal with 20ppm. This is desirable as I am looking to microsecond timers that would be accurate.

Can I use the watch crystal, create and use a clock based off this at 24Mhz?

I am trying to locate documentation on this and my searches do not amount to any thing.

Help is appreciated, regards.

Ken.

MotooTanaka · ‎Mar 08, 2020

Hi,

I'm sorry hearing that the USB Clock of 5LP does not have enough accuracy.

I tried with CY8CKIT-059. (5LP)

I'm afraid that there is no path from XTAL 32kHz to Master Clock.

The XTAL needs to be 4MHz ~ 25MHz.

Then I tried with CY8CKIT-044 (4200M)

If I set wco (32kHz) with 20PPM accuracy

We can trim IMO with WCO, so that IMO accuracy is +/- 0.2%

moto

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XTAL crystal for 5LP prototyping kit

XTAL crystal for 5LP prototyping kit

Re: XTAL crystal for 5LP prototyping kit