Question:
What would happen with the AD7124-8, when the programmable gain amplifier is set to 128 and the differential input voltage to 0.1 V (tip: what is a differential input?).
The reference voltage is set to 2.5 V
Power supply: AVDD = 3.3 V, IOVDD: 2.7 V
(Please keep the standard settings for everything else).
Please calculate yourself and simulate in the Virtual Eval Tool.
Answer:
The Sigma Delta ADC would saturate, since the gain of 128 in combination with the differential input voltage of 0.1V is too high for this setting. This is forbidden in the simulation. It requires you to lower the gain or lower the differential input voltage. Additionally you will also receive a note from the Virtual Eval Tool explaining this.