Kinetis Microcontrollers中的主题 Re: Contradiction in reference manual K02P64M100SFARM

Contradiction in reference manual K02P64M100SFARM

johnsmith3 — Tue, 22 Nov 2016 09:33:47 GMT

Hi all,

I'm using a MK02FN64VFM10 and want to use a 25 MHz external crystal.

In reference manual K02P64M100SFARM, on page 503: 26.5 External Crystal / Resonator Connections it says:

"When using low-frequency, low-power mode, the only external component is the crystal or ceramic resonator itself. In the other oscillator modes, load capacitors (Cx , Cy ) and feedback resistor (RF) are required."

I conclude from this that Cx, CY and RF are always *required*, with LF-LP being the *only* exception...

But the table on the same page suggests that for HF-LP, the "crystal only" configuration can also be used....

Can someone please clarify this?

Regards,

Re: Contradiction in reference manual K02P64M100SFARM

Hui_Ma — Fri, 25 Nov 2016 09:29:09 GMT

When customer using the system oscillator in low-power mode, Rf is integrated and must not be attached externally. So there doesn't need the external feedback resistor.

Customer can select to use the internal load capacitors (Connection 1) or external load capacitors (Connection 3). There doesn't with any restriction when using system oscillator in low-power mode.

Wish it helps.

Have a great day,
Ma Hui
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Re: Contradiction in reference manual K02P64M100SFARM

johnsmith3 — Fri, 25 Nov 2016 09:36:51 GMT

So i can use a 25MHz crystal without external capacitors and without external resistor?

Is this a reliable solution?

Thanks,

Re: Contradiction in reference manual K02P64M100SFARM

Hui_Ma — Mon, 28 Nov 2016 03:11:27 GMT

Yes, that's right.

Customer can use connection 1 way with a 25MHz crystal, without load capacitors and external feedback resistors.

Wish it helps.