We tried to design AD7768-4 for our sensor circuit , But I have a issue from ADC input pin. When turn on AD7768-4 and AINx+ and AINx- are floating , we can measure 5.28V DC on those pin. when we remove VDDIO1.8V then 5.28V vanish. What's Wrong? Below is our condition on AD7768-4. BTW, Does AD7768-4 has power on sequence?