AD7799 Conversion

I have AD7799 in my circuit with analog 5V supply and a separate 5V reference voltage. 

Internal Gain =1. Based on the datasheet analog inputs can not exceed 5V+30mV. But my analog inputs can read up to 5.5V (and power supply is still 5V). 

Does this have any impact on the conversions? May be the conversions be wrong. I expect when 5.5V is at the input, the output should be 0XFFF.

Thanks

  • +1
    •  Analog Employees 
    on Apr 21, 2021 11:23 AM

    Hi, 

    Looks like this question was just transferred from a different community and might be long overdue. However, for others who may find this a similar issue let me try to address this. 

    First, yes you are correct the absolute AIN voltage limits (unbuffered mode) is up tp AVDD + 30mV only so you cannot guarantee performance beyond this. The abs max rating is also limited to AVDD+0.3V so you must not exceed this specs to avoid any damage.

    Thanks,

    Jellenie