To Whom it May Concern,
The AD9680 data sheet is not clear about the temperature output on the FD_A pin.
Text on p.22 reads that the temp diode voltage can be output to the FD_A pin.
Typically such diode requires a very accurate current source. That implies a high input impedance requirement to ADC converting that voltage.
I couldn't find:
* whether an ext current source required (I assume not);
* FD_A parameters are defined in the digital out mode only. No info on whether there is a built in temp voltage buffer and what its output parameters are.
It's important in the case when I want to read temp-related analog voltage AND use digital output from the pin because digital input connected to the pin may have leakage acceptable for a digital circuit but too high for the analog output.
Any help on this issue would be greatly appreciated!