Can you ask the a/d guys something about the ADS1248.
There are current sources up to 1.5mA, and there is an internal 2.048V reference. Is there any ratiometricity or proportionality between these? Suppose, for example, the 2.048V internal reference dropped by 1% due to temperature effects. Would the current source drop by the same amount as a direct result of the drop in internal reference? This is not considering any separate effect temperature might have on the current source itself.
The data sheet claims the 2.048V internal reference must be enabled in order to use the current sources. This suggests they may be linked together somehow.
The reason for this question is because we are using the ADS1248 to read strain gauges. These use the 1.5mA current sources to excite the gauges and the internal 2.048 reference as reference for the a/d conversion itself. Just wondering if I can consider this conversion to be ratiometric as described.