ULPCD problem of PN5190

[Fanfei]

Hi expert,

I use pn5190 on my product , its a low power product , so the pn5190 is enter ULPCD mode when system is sleep.

After send the command SWITCH_MODE_LPCD(0x23), I received a GENERAL_ERROR_EVENT, and the GENERAL_ERROR_STATUS_DATA is 0x03.

The same firmware works fine on another type of PCB. Both PCB boards use the same power supply circuit but different antenna circuit.

Please help me to analyze this problem?

Many thanks

FanFei

[Fanfei]

Good day @EduardoZamora , thanks for your reply. 

I double check the design of both PCBs, and found the abnormal one connect the E3 F4 and C2 to the ground(package is VFBGA64). I'm not sure  it has anything to do with the problem.

The antennas size is different, and the abnormal one has touch pad around the antenna.

And this is the antenna circuit :

I can't swap the IC, but the same phenomenon on 4 boards, so I don't think its the IC.

I do notice the XTAL error, and my colleague is checking the circuit. 

I dont use the NFC Cockpit. I will try to use it.

The EEPROM seting is same. I had read out all the EEPROM setting and compare it  with the good one. 

[EduardoZamora]

Hi,

E3 and F4 are GND pins; C2 is an internal test pin, but attaching these pins to GND should not suppose an inconvenience.

I checked your antenna values, and it looks ok; however, could you please share the Smith Chart of your setup?

By any chance, are the "good" and "bad" ICs from the same batch?

Also, please check your inbox, I just sent you a private Community message.

Regards,
Eduardo.

[Fanfei]

Hi,
Sorry, we don't have the Smith Chart. And I'm not sure is the ICs from the same batch.
We use an oscilloscope to check the waveform of XTAL, then the IC enter UPLCD successfully. So we will check the XTAL circuit.
Thanks for your help ^_^

[EduardoZamora]

Hello @Fanfei,

Hope you are doing well.

Just to confirm, both PCBs are based exactly on the same HW design, but the only difference is the antenna, is this correct? What is the difference between both antennas? Is the antenna size different? Could you please confirm that each antenna was properly matched according PN5190 antenna design guide?

Can you share your antenna component values so I can try to simulate your antenna on my side?

Is it possible for you to perform an A-B-A Swap test to rule out that this behavior follows the IC?

According to PN5190 instruction layer, Section 4.4.1.2.4, this error should indicate Clock error and ADC error. These errors could be caused by XTAL or PLL not starting, and GPADC initialization failed.

There are some EEPROM considerations that need to be taken into account to properly set the power configuration being used, CLK, ULPCD (refer to PN5190 Data Sheet, Chapter 9.25). By any chance, are you using our recommended NFC Cockpit to configure the relevant EEPROM settings? Were the same settings applied to both boards?

Regards,
Eduardo.