I want to put a resistor in the front stage and adjust the gain.
What is the input impedance of the ADuM7702?
Hi,
In the analog input section of the datasheet it is written: "The pseudo differential analog input of the ADuM7702 is implemented with a switched capacitor circuit.". So it means dynamic load rather than resistive, what is specified:
In the examples 10 Ohm external impadance can be seen, so I think it is not recommended to use higher, because due to the dynamic input current it will introduce error. Taking the 10 Ohm at full-scale input you just get an error close to the resolution of the ADC.
Zoltan
Hi,
In the analog input section of the datasheet it is written: "The pseudo differential analog input of the ADuM7702 is implemented with a switched capacitor circuit.". So it means dynamic load rather than resistive, what is specified:
In the examples 10 Ohm external impadance can be seen, so I think it is not recommended to use higher, because due to the dynamic input current it will introduce error. Taking the 10 Ohm at full-scale input you just get an error close to the resolution of the ADC.
Zoltan
