As well as the inverse Sinc filter for the first Nyquist band, an inverse sinc filter is also available for the second Nyquist band when the RF-DAC is operating in mix-mode. This is a half-band filter with nine taps, the flatness is < ±0.033 dB within the 80% Nyquist band.
The coefficients and frequency response of the inverse sinc filter for mix-mode are shown as follows. The N(bit) is the bit width of the coefficients; use for normalized coefficients.
N(bit) = 10 Center Tap: 1066 First Half: 5,0,25,1
Figure 1. Inverse Sinc Filter for Mix Mode
The flatness of the inverse sinc filter in the second Nyquist band is shown as follows.
Figure 2. Flatness of Inverse Sinc Filter for Mix Mode