PN7462B v2.2 EMC and Antenna Tuning capacitor value

[poneponecar]

Hi,

I am following the n336911 - AN11706 PN7462 family Antenna design guide (1.1).pdf to fine tune my customized antenna.

As the tutorial showed, it could be divided to two parts: 1. the EMC filter, and 2. the matching circuit.

When I refer to the schematic of PN7462B v2.2, I found more components than shown in the tutorial, so I tried to match them with the tutorial.

The EMC filter should be C28, C29, C31, C32

Matching should be C35, C37, C47, C49, C40, C41, C43, C46.

Then what's the purpose of C38, C39, C44, C45 as marked in the red circle?

[Kan_Li]

C45 and C39 are NC parts on that board, and C44 and C38 are part of the EMC Filter, EMC filter capacitances.

Have a great day,
Kan

-----------------------------------------------------------------------------------------------------------------------
Note: If this post answers your question, please click the Correct Answer button. Thank you!
-----------------------------------------------------------------------------------------------------------------------

[poneponecar]

Hi Kan,

Thanks for the prompt reply. 

With  C28=120pF, C29=27pF, C31=100pF, C32=27pF, C38=120pF, C44= 120pF, how should I correctly fill these values into the excel sheet?

I assume the C01 is 120+27 = 147pF, and the C02 is 120pF, the computed EMC filter cutoff frequency is 14.2Mhz.

Is it correct?

Also, is there any particular reason to separate the EMC filter capacitors to two different sides of the PCB?

Thanks,

Jay