This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

ADS1220: one question about the power down mode of ADS1220

Part Number: ADS1220

Hi,

Our customer send the POWERDOWN command to ADS1220 but the total system current is not changed obviously.

So, do we have a simple way to verify if ADS1220 is in power down mode or not?

Thanks.

  • Hi Oliver,

    Depending on the ADS1220 configuration the POWERDOWN command may not change the current that much as compared to the standby (or idle) state as compared for the analog supply.  The POWERDOWN command will turn off the IDACs (if they are turned on) and open the low-side switch if it is being used.  In single-shot mode after the conversion has completed, the ADS1220 will go to a low power state by turning off the internal oscillator and all analog circuitry except the IDACs (and opening the low-side switch if configured to do so).  Where a power difference will be seen for the ADS1220 itself is when using the POWERDOWN command when the IDAC current sources are used.

    If you want to see if the POWERDOWN command is working, then I would suggest using the IDACs and seeing if the IDAC current stops when the POWERDOWN command is issued.

    Best regards,

    Bob B

  • Hi Bob,

    Thanks for your explanation, consider this chip ADS1220 is used in a wearable device, the standby current is the main concern for our project. as the datasheet description, in power-down mode, the current of AVDD is 3uA and DVDD 5uA, what's the configuration process? then we can achieve that low current result.

    thanks!

  • Hi user3687315,

    Can you tell me what configuration you are writing to the registers? If you have set the ADS1220 to continuous conversion mode, the device will not go to a low power state unless the POWERDOWN command is issued ( or a register write to set the ADS1220 to single-shot mode). After the current conversion completes following the POWERDOWN command the ADS1220 should go to the lower power mode. However, if you write a new configuration to the ADS1220 you will wake up the device again.

    Please confirm your registers settings, and any communication sequence before and after POWERDOWN. Also explain how you are attempting to measure the current, such as is this a direct measurement or indirect? What values of current are you seeing?

    Best regards,
    Bob B