Hi Ajayt, The reference input voltage measurement uses a voltage divider which is prone to lot to lot and device to device variation. This voltage divider will also drift. So the short answer is yes, the measurement will have noise and drift that differs from the normal input path with respect to an analog input into the mux. The purpose of the reference voltage input measurement is not to get a precise voltage measurement, but rather to be used in cases such as sensor diagnostics. For example, a 3-wire RTD using a low-side reference utilizes 2 current sources for lead cancellation in the measurement path. If the one of the current sources is missing due to a broken lead, the measurement will be 1/2 of the normal reference measurement as only 1/2 of the current is exciting the reference resistor. For this case you do not need a precise measurement of the reference. As far as stability of the reference voltage measurement, there will be drift with temperature and there are no performance guarantees. If the measurement is held at a stable temperature (room temperature for example), the result should be relatively stable. Best regards, Bob B
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