We would like to use this ADC to measure some analog voltages in the range of 5.8volts. do we need to use +15V and -15V supplies or we can live with+6 and -6 volrs. What about AVDD in this case?
AVDD and DVDD supply the ADAS3022 analog and digital cores, respectively. AVDD and DVDD should be 5V. This is also specified in the datasheet under“specifications” on page 5. For your reference I’ve copied the relevant section below.
The high voltage bipolar supplies (VDDH and VSSH) on the other hand, are a little bit more tricky. Both of them are required and must be at least2.5V larger than the maximum input. More information can be found on page 29 and 30 in the datasheet under “power supply”.