The coefficients and frequency response of the IMR interpolation filter are shown as follows.
IMR Filter Coefficients
N(bit) = 12 Center Tap: 4096 for low pass; -4096 for high pass First Half: 10,0,-23,0,48,0,-89,0,154,0,-256,0,432,0,-813,0,2588
Figure 1. RF-DAC IMR Filter Frequency Response
The following image shows a zoomed plot of the cross region between high and low pass filter modes.
Figure 2. IMR Filter Frequency Response-Zoom