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LTC6803-1 Chain Communication Issue

Category: Hardware
Product Number: LTC6803-1

Hi,

I'm developing a system which incorporates a 30 cell battery stack and 3 LTC6803-1 Battery Stack Monitor ICs for monitoring the cells.

The circuitry is based on the example provided on page 13 of the LTC6803-1/LTC6803-3 datasheet.

I can write commands to the first LTC6803-1 in the chain and read valid data back from it, e.g. write/read configuration data. However, I am unable to write or read from the other LTC6803-1 chips further up the chain.

When I probe the buffered SPI signals, CSB0, SDOI & SCK0, I can't seem to read a recognisable signal, even on SCKO (I currently don't have the capability to log current measurements at the magnitude indicated in the data sheet for current based logic levels and am assuming that some form of pulsed waveform would available to see on a scope).  

VMODE and TOS are set correctly for the three monitor chips and there's a 1K pullup resistor on SDO of the first LTC6803-1.

I would be most grateful for any help or guidance that anyone can provide on this matter.

Best regards

 

Rob

  • Hello Rob,

    Thank you very much for reaching out and for your participation in this community. I have contacted the ADI experts on this device to help respond to this query. We hope to give you an update as soon as possible. You can also try reaching out to local FAE to provide support on the product.

    If you can give me your project information and estimated annual usage (EAU), I can help connect you to a local FAE. Thanks.

    Regards,

    Nino

  • Hello Rob,

    I have consulted product experts of this device to help you answer this query. 

    Can you provide your schematic to be able to confirm that all 3 of the LTC6803-1 are set to the correct mode and connected correctly to each other? And also how are the 30 cell battery connected to the 3x LTC6803-1?

    Regards,

    Nino

  • Hi Nino,

    Thanks for your reply.

    We managed to find the problem. Our PCB manufacturer had fitted the diodes on the SPI lines back-to-front.

    Apologies for not closing the ticket.

    Best regards

    Rob