CSU V2.2A stackup pcb - BQ79718 and CC2662R

Part Number: CC2662R-Q1
Other Parts Discussed in Thread: BQ79718V-Q1,

Tool/software:

Hello,


I am working on a new design that uses the cell monitor BQ79718V-Q1 and CC2662R-Q1. As reference design I have TI CSU V2.2A board physically and also the Altium project. After finishing schematics next step is routing the PCB.

For the PCB antenna I am using the same 2.4-GHz inverted antenna tuned to 50 Ohm following TI recommendations, app note below:

www.ti.com/.../swru120d.pdf

The app note says: "The results presented in this document are based on an antenna implemented on a PCB with a 1-mm thickness using standard FR-4 material"

It seems that the best wireless performance can be achieved using 1 mm final thickness pcb antenna. By the other hand, in eval kit CSU V2.2A Altium project, the stakup manager shows also 1 mm final thickness but in the mechanical layer it appears: Thickness: 2.0 mm +/-10%.

Also I've measured with a caliper the PCB thickness and it is 2 mm thickness.

Which is the correct thickness that I should use in the design?

Thanks in advance

 

  • Hello,

    The performance difference should be minimal between a 1mm thick board and 2mm thick board. If a 2mm thick board is prefered for your design, there should be no concern about being able to achieve similar performance detailed in the SWRU120d app note. Ensure you include a matching network at the input of the antenna to provide the ability to tune the input impedance of the antenna to 50ohms would be my only recommendation. Please refer to SWRA726 for more details. 

    Regards,

    Andrew

  • Hello,

    Yes, matching network is included in my design. So, I understand that a final thickness PCB of 1.6 mm is also feasible having the matching network on the PCB. 

    Is this correct?

    regards, 

    js