ADS1147: The data read from the register is inconsistent with the configuration.

Part Number: ADS1147

Tool/software:

Here are 2 issues we found, during the long-term testing of the resistance detection function

1.For the registers configured through SPI, when repeatedly reading them, there is a probability (occurring about two or three times in an hour) that the data read from the registers may not be consistent with the configuration, but reading them again will be consistent.

The following image shows the operation of reading register 0x03 (which requires adding 0x20 during communication, so it is 0x23) via SPI. The data expected to be read from this register is 0x01, but the actual reading is 0x07.

2. For a fixed resistance value, continuously reading its converted ADC results may occasionally show a sudden drop in the read value; however, reading it again will restore the value.

  • Hi YUCHUN GUO,

    I assume you have sent the SDATAC command prior to reading / writing commands, correct?

    Do you stop conversions before you send these commands?

    Is there any digital isolation in your system? Can you send a schematic?

    Are there any other devices sharing the SPI bus with the ADS1147

    Can you explain what "sudden drop in the read value" means? Can you provide the data you are getting so we can review? Please include the ADC register settings as well as the raw ADC data in hex

    -Bryan