Can the Vdda of the A/D converter be connected to any other source but Vdd on the STR75x devices. For instance, if the device is running at 3.3V, is it acceptable to connect the Vdda to 2.5V. Thanks, Martin.
The Vdda of the A/D converter must have the same level voltage as the Vdd of IO. it could not have different voltage level. Please refer to STR75x Reference manual regarding power supply pins recommendation. Thanks.