Which reference should be used with the AD719x?
A low noise reference source is required to achieve the best performance from the ADC. Suitable external references include the ADR421 and ADR431. It is recommended to decouple the output of these references to further reduce the noise level.
In applications such as pressure measurement systems or weighscales, the excitation voltage for the bridge can be used to derive the reference voltage for the ADC also. If the excitation voltage is equal to or less than AVDD, it can be connected directly to the reference pins of the AD719x device as the AD719x can accept reference voltages up to AVDD. In these applications, the affect of the noise in the excitation voltage will be removed as the application is ratiometric.
For weighscales applications (0-20mV max. in input pins), It´s better connect to refin+/- pìns a voltage divider of AVDD?. Which is the best reference voltage for weighscales applications?
For weighscale applications using a ratiometric setup is advised. This is where the reference is derived across the bridge sensor. This is detailed in the applications section of the AD7190 data sheet.
Retrieving data ...