NFCのトピックHTRC110 signals

HTRC110 signals

sandorbedo — Tue, 28 Aug 2018 07:03:58 GMT

Hi,

I work on a project with this IC and as I built my circuit I have some questions:

For first here is the schematic:

I tried to calculate all the necessary data, but the Rdem_in parameter is not present in any document.

Is this changeable with registers or is this a fix value?

- As I measured the TX1 pin it is okay. The 125kHz signal is there (1)

After the capacitor (2)

Directly before the coil I measured the next. I assume that I got it because of the coil. So from my opinnion it should be okay. (3):

Unfortunately I have no idea why I got this.

And as I see, because of this I have problem with the output sine signal as well (4):

As I measured these two signals:

Does anybody have any idea what I make wrong?

Because right now I have no more idea.

jimmychan — Tue, 04 Sep 2018 15:19:51 GMT

The value of Rdem_in is in the datasheet Table 18.

sandorbedo — Tue, 04 Sep 2018 19:50:43 GMT

Thank you, yes there is the value, but what is the exact value of this?
Because it describes, that it is from 17k to 33k.

What does it depend on the value of it?

Is this changeable?