Analog switch power supply

[vikash23]

I am using ADG715 analog switch. I am switching analogue signals. I would like to know if the power supply to the analog switch should be analogue power supply or digital power supply. ? I have connected AGND and DGND using 0R0 link.

Since it says analog switch I thought the power supply should be analog and not digital.

please help me with this topic.

 

[BradtheRad]

The ADG715, and the device from which it gets control signals, probably ought to be powered by the same supply.

I could be wrong. I did not see anything specific on the datasheet. Nor did it state that the S1-S8 & D1-D8 pins have anything directly to do with the power supply.

 

[FvM]

I see contradicting aspects that could reason the assignment to one or the other supply node.

- bus operation causes noise injection to the supply

- power supply noise shows a certain feedthrough to analog switch nodes

Unless the analog circuit connected to the switch involves ultra low signal levels, digital supply should be O.K. Otherwise, the I2C pins should be connected to a separate bus that's not controlling other devices so it can be held quiet in normal operation.