Pls help check schematic diagram

[Wu Yewan]

Application: Find my tag

Customer: SHENZHEN FEASYCOM TECH CO LTD

Find my tag.7z

[Nissanth]

Hi, 

Feedback 1: C35 should be 2.2 nF on DECRF pin. 

Feedback 2: Add a 3.9 pF capacitor at nRESET, placed right at the pin, as in the reference. See image below. 

Reference below,

Feedback 3: The ANT matching network does not match Nordic’s reference. The first series inductor is missing, and the component values differ. Copy the reference as shown below. 

Reference below, 

Feedback 4: Both pin 5 (P1.04) and pin 6 (P1.05) are labelled UARTE20_TXD. One of them must be UARTE20_RXD.

Feedback 5: The NFC net labels are crossed. Pin 3 (P1.02/NFC1) goes to net NFC2, and pin 4 (P1.03/NFC2) goes to net NFC1.

Feedback 6: Typo on pin 21 

Rest of the schematic looks fine. Make sure the footprint is close to our reference schematic, most important for the ANT network and the supply. If you can send me the datasheet for the crystals, I can check them too. 

Best regards,
Nissanth Karunanithy

[Wu Yewan]

Hi Team,

The R&D  has a question ,  The nfc coil is completely symmetrical. Is there any problem with network switching? Or, what impact will the forward or reverse insertion of the coil have on card reading ?

Thanks,

Curry.

[Wu Yewan]

Or perhaps it's just that the online name is reversed, and the performance is not affected.
The reason for the engineers' crossover is that when laying out the pcb, they found it was not smooth, but after the crossover, it became smooth.

Thanks,

Curry.