kuohsi said:
hi all, I am a rookie of this board.
Does anyone know what is the Vref which in the attached Figure?
and how many amplitude of Vref?
thank you!
Hi,
The Vref shown in the figure is the voltage associated with the feedback DAC.
If the output of the comparator is high, +Vref/2 is selected and fed back to the switched capacitor filter,and when the comparatpr output is low, -Vref/2 is fed back.
Usually, the voltage is multiplied by a feedback coefficient (implemented as capacitor ratios in a switched capacitor implementation.
The choice of Vref depends upon the supply voltage in the technology, implementation etc.
Hope that helps.
Bharath