LTI Filter for DAC Reconstruction

1. What type of filter is used for reconstruction Why?
2. How does a reconstruction filter work?

What type of filter is used for reconstruction Why?

The reconstruction filter, at the output of the DAC, is usually a high order Bessel or elliptic filter used to low pass filter the analog output from the DAC.

How does a reconstruction filter work?

Thus, the reconstruction filter smooths the waveform to remove image frequencies (copies) above the Nyquist limit. In doing so, it reconstructs the continuous time signal (whether originally sampled, or modelled by digital logic) corresponding to the digital time sequence.