Good day!Read of theme "AD7788: Input ranges"I have a question to the expert answer. In documentation for REF3040 I found a similar circuit.
A specialist in the above subject, a similar connection recommended AIN- input to expand the input voltage. However, in the specifications for REF3040 input voltage range has not changed. Where the error lies?
As mentioned on the AD7788 datasheet it can have a unipolar and bipolar ranges. The Ain+ input can be referred to the Ain-. As an example, when using 2.5V on Ain-. The input voltage range is from 2.5V to 5V but when it is in bipolar mode the range will be from 0V to 5V. You can program the U/B bit in the mode register to select a unipolar /bipolar input. ADI has 2.5V reference voltage sources recommended like the ADR381 and ADR391. If you have other questions, please let us know.