LTC6813: 4-wire SPI problem with DC2350A-B

We are trying to communicate with  the LTC6813-1 on demo board DC2350A-B via 4-wire SPI from a 3.3V microcontroller host with  5V-compatible inputs.

After addressing /CSB  for 500µs, Vreg turns on for 2 seconds. When transmitting read command RDCFGA there is no answer on MISO.

The SPI configuration is following: Speed 1MHz and mode 1,1.

Command RDCFGA: Byte0: 0x00, Byte1: 0x02, Byte2: 0x2B, Byte3: 0x0A, Byte4-11:0x00 (to get clock for 12 bytes).

The /CSB  is set low before sending and set high after  12 bytes. No answer from LTC6813.

 

Configuration DC2350A: SDO pullup to VDD (tried 3.3 and 5V), all jumpers JP1-JP4 in 0-position, 18 cells Li-NMC connected, ISO-SPI not used.

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  • Hey,

    Sadly, I'm facing the same problem. Were you able to resolve the issue?

    I'm using isoSPI and I have confirmed that the RDCFGA command (same one you've used) is transmitted correctly from the LTC6820 to the LTC6813-1. After receiving the mentioned command, the LTC6813-1 exits sleep mode for approx. 2 seconds (Vreg = 5 V during this time). So basically the exact same behaviour as you've described. I've already tried multiple SPI speeds (ranging from ~250 kHz to ~1 MHz).

    The problem is that I never get a response from the LTC6813-1. Not getting a response (null) equals to a logic '1' and thus I only receive 0xFF eight times (6-bytes data and 2-bytes CRC).

    Best regards,

    Dominik

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  • Hey,

    Sadly, I'm facing the same problem. Were you able to resolve the issue?

    I'm using isoSPI and I have confirmed that the RDCFGA command (same one you've used) is transmitted correctly from the LTC6820 to the LTC6813-1. After receiving the mentioned command, the LTC6813-1 exits sleep mode for approx. 2 seconds (Vreg = 5 V during this time). So basically the exact same behaviour as you've described. I've already tried multiple SPI speeds (ranging from ~250 kHz to ~1 MHz).

    The problem is that I never get a response from the LTC6813-1. Not getting a response (null) equals to a logic '1' and thus I only receive 0xFF eight times (6-bytes data and 2-bytes CRC).

    Best regards,

    Dominik

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