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LP-EM-CC2340R5: BOMs do not match

Sonny Gill
Prodigy 40 points
Part Number: LP-EM-CC2340R5

Tool/software:

Good day. Components Z60 and Z62 in the BOM do not match the Orcad schematic. Z60 and Z62 are 12pF in Orcad schematic. In the pdf schematic and the BOM, Z60 and Z62 are 1.2pF and .7pF respectively. Which one is correct? I have non-working prototypes where I used Z60=1.2pF, Z61=5.1 nH, and Z62=.1pF per my own simulations. Being as its not working, I will switch to TI values, but need clarification as to what they are. For completeness, could you please give me the correct values for

Z60, Z61, Z62, C33, L33, C34 and CA2

My reference board says BOM Rev B. If you could make this clarification and provide the entire BOM rev B, that would be very helpful.

Thanks

  • 0
    TI__Mastermind 32390 points

    Hi,

    In the reference design LP-EM-CC2340R5 Design Files, the schematic and BOM are Rev A and the antenna match values are Z60: 1.2 pF, Z61: 2 nH and Z62: 0.7 pF. These values are valid for the PCB antenna match on the LP-EM-CC2340R5 board.

    If your design is not exactly the same as the LP-EM-CC2340R5 board, then you will need to find new antenna match values for your design. i.e. your design will have a different GND plane size and different antenna loading due to mechanical housing distance, casing material choice and application placement of your product.

     

  • 0 in reply to RGW
    Prodigy 40 points

    Thanks.  Why the discrepancy between the orcad values and the schematic?  My antenna design matches the TI reference design, the network connecting the ic to the antenna has been carefully designed to be 50 ohm, yet this does not work.  The matching network was carefully designed per the physical antenna model (matching network determined by smith charts).

    I had the first rev board designed by a contractor and she proceeded to use a different antenna with Z60=12pF, Z61=0 nH, and Z62=12pF.

    The caps matched the orcad values.

    This board worked!  No analysis, crutty network connecting the IC to her custom antenna and seemingly incorrect matching network.

    Problem is, no real signal range.  Her design is bad, signal range is a few feet.  Rev B which I carefully designed, not functioning at all.

    So my question to TI remains.  What are the capacitor values on the ref design?  12pF and 12 pF or 1.2pF and .7pF?  The documents don't match.

  • 0 in reply to Sonny Gill
    TI__Mastermind 32390 points

    Hi,

    The CAD file in the reference design is Cadence Allegro shows for Rev A BOM option the following which matches the schematic and the BOM. These are the values you should be using for your antenna match as a start value. But as mentioned in last thread, these values will always be unique for each particular design.

    If you are using a CAD translator from Cadence Allegro to Orcad then perhaps this is basing the translated design on the "core design" which is just a foot holder for these components and not the BOM Rev A design.

     

  • 0 in reply to RGW
    Prodigy 40 points

    Got it.  Thank you. For completeness , does the rev B BOM change any electrical components?

    Thx