topic Re: Can the KE02 accept a square wave external clock reference? in Kinetis Microcontrollers

Can the KE02 accept a square wave external clock reference?

babbott — Mon, 16 Oct 2017 13:16:42 GMT

I'd like to use the KE02 with an external clock reference to drive the oscillator of the micro-controller. Can the KE02 accept a square wave external clock reference and if so,what are the voltage specifications?

Thank you.

Re: Can the KE02 accept a square wave external clock reference?

xiangjun_rong — Tue, 17 Oct 2017 08:18:18 GMT

Hi,

Pls refer to the following figure in the MKE02P64M40F0SF0.pdf.

you can connect the clock source to the Extal pin, it is okay.

Hope it can help you.

Xiangjun Rong

Re: Can the KE02 accept a square wave external clock reference?

babbott — Tue, 17 Oct 2017 16:07:29 GMT

Thanks. My question is whether or not the shape (square or sine) matters in this application. I have an external clock attached to the EXTAL pin but I am wondering if it needs to be a square or sine wave (or maybe it doesn't matter)?

Re: Can the KE02 accept a square wave external clock reference?

mjbcswitzerland — Tue, 17 Oct 2017 17:41:42 GMT

Hi Brent

Regards

Mark

Kinetis: http://www.utasker.com/kinetis.html
KE02: http://www.utasker.com/kinetis/FRDM-KE02Z.html / http://www.utasker.com/kinetis/FRDM-KE02Z40M.html

Re: Can the KE02 accept a square wave external clock reference?

xiangjun_rong — Wed, 18 Oct 2017 03:37:39 GMT

Hi, Brent,

Mark gave you the clock source frequency spec. Regarding the clock source voltage spec, it also complies with the digital imput voltage rule, the high logic voltage must be greater than 0.7*VDD, the low voltage must be less than 0.35*VDD.

Hope it can help you.

Xiangjun Rong