topic Re: PN7642 - Initial Calibration in NFC

PN7642 - Initial Calibration

MPEngineering — Mon, 22 Sep 2025 10:38:25 GMT

Hello Community,

i have a custom PCB with PN7642.

The Datasheet says, that before turning on the RF part, an initial calibration needs to be done.

Is there any further documentation about this than:

1. Write EEPROM configuration NOV_CFG_CAL.
2. Write REGISTER TX_NOV_CALIBRATE_AND_STORE_VAL_REG.
3. Write EEPROM configuration NOV_CFG_CAL.?

Which values should be set?

Thank for helping.

Best regards

Oliver

Re: PN7642 - Initial Calibration

KaiLi — Tue, 23 Sep 2025 02:38:52 GMT

Hello @MPEngineering

It's recommended that you can run SDK the example

Best-in-Class NFC Frontend with Integrated MCU | NXP Semiconductors

and download:

Re: PN7642 - Initial Calibration

MPEngineering — Tue, 23 Sep 2025 08:39:35 GMT

Hey @KaiLi ,

thanks for replying.

Yes, i have the SDK. So with flashing an example its calibrated?
I looked for the definitions of the Registers in some examples and also in the API Reference Manual.
I don´t see them.

Maybe my question was a bit unclear.
I want to know, what i have to write into REGISTER TX_NOV_CALIBRATE_AND_STORE_VAL_REG.
Cause there is no further explanation. Its 2 bit r/w register. What happens if i write 0x1, 0x2 or 0x3 into it?

NOV_CONFIG_CAL is clear. First write 0x01 for cold boot FW calibration and after succesfull calibration write 0x02 to reference to NOV_CAL_VAL1 and 2.

Best regards

Oliver

Re: PN7642 - Initial Calibration

KaiLi — Wed, 24 Sep 2025 05:56:12 GMT

Hello @MPEngineering

This part should be encapsulated, and recommends to run the project:

PN7642_MCUXpresso_SDK_02-15-003_PUB\boards\pnev7642fama\nfc_examples\pub\NFC_Config, and select "RFLD_NFCLD_CONFIG"

After that, the device can be initialized and calibrated.