Hello there,
I have a question about the absolute ratings of the AD7708.
According to the datasheet:
AVDD to DVDD . . . . . . . . . . . . . . . . . . . . . . . . –5 V to +5 V
Typically, in my design: the AVDD is a 5.7V and DVDD at 3.3V; within the above limits.
The thing is that at power up, AVDD is provided before DVDD and theoritically, it
could have 5.7V between them.
When I look at the voltages during startup, the difference is limited to around 1.8V.
I don’t know what is limiting it; is it something internally?
I am also planning to delibarately shut-down the DVDD for power savings
and I would like to verify what are the constraints.
Please advise,
Teodor