FDC1004: Design review needed on the FPC design

Shyam,

A few comments and questios:

1. C14 and C15 are kind of large compared to the SHLD driver max load capacitance of 400pF. They should be made smaller.
2. What is the reason for C13? It is attached to CIN3, which appears to be provisioned as a sensor. The 0.1uF will most likely dominate any measurement.
3. Be sure to confirm the 10k values for R59 and R60 will work for your application. Our EVM uses 5k,
4. How device settings will you use for your sensors, CIN1 - CIN4?
   
   Regards,
   John

Thank you so much John, I got the reference for FDC1004 from here: https://www.ti.com/lit/ug/snau163c/snau163c.pdf?ts=1674682213814&ref_url=https%253A%252F%252Fwww.ti.com%252Ftool%252FFDC1004EVM page number 40.

As of now I am not planning to populate C14, C15 and C16, do you need me to populare them? If so, I will change C14 and C15 to 51pF (or) less since the trace length on the FPC has increased.

Also, we are doing an EVK for now, so we need an ability to put the device in any possible setting. Which means have all the necessary components on the board to do it. 

Also, how do you feel about the layout? length of the FPC, thickness of the level trace and shield trace also the stackup.

once again, thanks a ton for the review so far.

Shyam,

If possible, please try to use the same R & C values as in our EVM. 
Keep traces and wires as short as possible. 

Are you using single-send, differential, or out-of-phase sensors (CIN1 - CIN4)?

Regards,
John

Sure, will try to use the same R&C values on the FDC1004 side. We are trying to use out of Phase sensors. Is the FPC looking good from that perspective? Since there is no clear recommended calculations for the FPC, I had to do a lot of guess work here. Want to make sure if it looks good

Especially the length, trace width, spacing between the traces and thickness of the layers.

Also pins 1, 8 and 10 are not connected on the FPC reference design here: https://www.ti.com/lit/ug/tidu736a/tidu736a.pdf?ts=1674681990613&ref_url=https%253A%252F%252Fwww.google.com%252F. Is that correct?

Got it, just want to get your thoughts on the FPC if you think for the length we have designed for, it will work. I am more worried about the total capacitance for the length here.

Got it, thanks John.