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ADS124S06: Unused GPIO pins

Genius 14060 points
Part Number: ADS124S06

Hello,

 

ADS124S06 datasheet recommends to tie unused GPIO output pins to AVSS through a pulldown resister and set the output to 0.

ADS124S06’s default setting for GPIO pins is output. So I don’t think there is any risk to leave these pins floating because there are always output pins.

Why does the datasheet recommends to tie them to AVSS with pull-down? Is there any risk or concern?

 

Regards,

Oba

  • Hi Oba,

    For the ADS124S06 the default mode for the GPIO configuration is output and zero if the GPIO are configured as GPIO (GPIO enabled).  The default value for the ADS124S06 is GPIO disabled.  See the note under Table 43 in the datasheet on page 85.

    Is the pulldown required? No, but it is recommended to prevent any accidental writing of the configuration register to make the GPIO an input (where the pulldown acts as a logic level input to prevent the input from floating) and as a current limit if the GPIO is accidentally made a logic high as a GPIO output.  A pullup could also be used instead for the same purpose.  

    As you mentioned the pin could be left floating if the GPIO is set to an output and the risk is low that it could be accidentally set to an input.

    Best regards,

    Bob B

  • Hello Bob,

    Thanks for your reply.

    I checked the datasheet again and confirmed GPIO is disabled for the default as you mentioned.
    ADS124S06 doesn't support AIN8 ~ 11 function. And GPIOs are disabled for the default.
    What is the mode of these pins right after reset?
    Does the user have to change the mode to GPIO output or is it OK to just leave the setting as the default in this case(floating)?

    Regards,
    Oba

  • Hi Oba,

    If the GPIO pins are unused as per datasheet "For unused GPIO pins on the ADS124S06, leave the GPIOCON register set to the default register values and connect these GPIO pins in the same manner as for an unused analog input." So yes, you can leave the pins floating.

    Best regards,

    Bob B