Vref, Bias and Vint part of circuit. what are their voltages?

[shemo]

vref , Vint and Bias all defined as inputs, but the circuit in 1.png shows vint has a filter cap C72 to ground.

1)so what's voltage of vint, which supposedly an input?

2)same with vref has a filter cap C76 to gnd. what 's the voltage of vref?

3)Bias has R28 to gnd. why do you need a resistor there?

 

[BigBoss]

There is a biasing/reference voltage generator in it and resistor is used to define internal bias current in the IC.Cap has been used to get a stability due to feedback nature of these kind of circuits.These voltages should normally be expressed in its datasheet.If not, you have to follow recommended values as are..