Powering a mixed signal board AVDD or DVDD for other IC's other than ADC

I have a circuit which reads from an electrochemical sensor IC. The block diagram of the circuit is given below.

It contains two voltage regulators for powering the AVDD and DVDD of the ADC.

From the electrochemical sensor IC, the output is connected to MUX and from MUX the signals are going to the ADC.

For 'RE' signal it is first going to a bufferthen it is going to MUX after that to ADC. ADC is controlled by an STM32 evaluation board.

My question is the MUX is a digital device but the I/P signal going to MUX is analog. Do I need to power MUX with AVDD or DVDD?

I can power buffer with AVDD becuse it is an anlog buffer. Please correct me if I am wrong.

Please see the datasheet of my components below.

ADC

MUX

BUFFER

LDO