OM27160B1HN with SPI interface not working with 3.3V

[Dharmit_m]

We created our custom NFC board with OM27160B1HN (PN7160) with SPI interface support, based on the reference provided for supply voltage in the datasheet it is clear that we can give 3.3V for both VBAT as well as VDD(PAD) and VDD(UP). With this configuration board bring-up was successful but NFC tag was not detected because antenna tuning section was not generating 13.56MHz.

But when we gave 5V to both VBAT as well VDD(PAD) and VDD(UP), it circuit started detecting the tags as it was generating the required 13.56MHz.

Can you tell us the correct configuration we should follow while giving the input supply for VBAT, VDD(PAD) and VDD(UP), also if we need to make any changes to the internal registers.

Kindly do the needfull.

[danielchen]

Hi Dharmit_m:

I would suggest you refer to AN13892

https://www.nxp.com/docs/en/application-note/AN13892.pdf

chapter 2, which power configuration to choose.

PMU configuration 

Regards

Daniel

Regards

Daniel

[Dharmit_m]

Hi Daniel,

I have referred the AN13892 and the suitable configuration we have used is CFG1 which is used in case of Battery-operated device. I am attaching the schematic of my custom board for reference. Also kindly share the PMU configuration sheet and provide information on NXP_TVDD_CONF register settings.
Currently I am interfacing my custom board with the raspberry pi and using the NFC factory test application, so how to set the above-mentioned register using this demo application.

[danielchen]

Hi:

please refer to below example

Regards

Daniel