PN7160调试疑问请教

cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

PN7160调试疑问请教

505 Views
sheldor0321
Contributor I

各位前辈、道友好,小弟使用PN7160设计实现NFC的读卡功能,目前调试发现VBAT、VDD(UP)和VDD(PAD)采用3.3V供电,10PCS有1PCS出现读卡异常,现象为读不到卡,用示波器挂测电源也是稳定没有掉电或者回沟低于标称的Vmin(2.8V),然后把整体的输入电压抬高到4.0V就可以正常读到卡,不太明白其中的原因,我原本的猜想是供电能量不够RF端的发射,但是示波器挂测又看不到电压跌落,请各位大神指点迷津,谢谢~

下面附上原理图

sheldor0321_0-1668592710383.png

 

0 Kudos
3 Replies

490 Views
KellyLi
NXP TechSupport
NXP TechSupport

Hello @sheldor0321 

After checked your schematic and two suggestions for your reference:

1. Vbat is the main power supply of the NFCC, Vdd(PAD) is the power supply for the host interface and GPIOs. Vdd(UP) is the power supply allowing to generate TXLDO. Their typical operating voltages are different. So, Vbat and  Vdd(UP) could be connected to 3.3V, and then it would be better to power Vdd(PAD) separately.

NXF92074_0-1668668084806.png

2. For the anormal board on your side, it is recommended that you do a comparison test between normal and abnormal to determine whether VDD(TX) pin is within the normal operating voltage range. The voltage level on TX output buffer is coming from VDD(TX) and this pin is powered internally by the PN7160 thanks to the TXLDO block. The output voltage of this TXLDO can be set between 2.7 V to 5.25 V depending on the VDD(UP) voltage.

Hope the above reply can help you!

Best Regards,

kelly

0 Kudos

479 Views
sheldor0321
Contributor I

Hello kelly,

  Thanks for your reply!I have done comparison test between normal boards and abnormal boards,on the normal board VDD(TX) pin is within the normal operaing voltage range,but on the abnormal board VDD(TX) pin is no voltage output.My doubt is that VDD(UP) connected to 3.3V,why do some boards work and some don't work.Then I raised VDD(UP) voltage to 4.0V,the abnormal board works properly.Can you tell me the reason for this problem.

  Best regards!

0 Kudos

473 Views
KellyLi
NXP TechSupport
NXP TechSupport

Hello @sheldor0321 

 Vdd(PAD) is the power supply for the host interface and GPIOs. I think there may be inconsistencies in the default state of the chip that cause some GPIOs to leak electricity, which leads to some boards abnormal. So, two suggestions for you:

1. Vdd(PAD) Vdd(UP) and Vbat are powered separately, like the following would be better:

NXF92074_0-1668750606528.png

2. Initialize all Gpios and the perpherals by software, make sure that the initial state of all boards is consistent.

You can try the above action to see if it works.

Best Regards,

kelly

 

0 Kudos