FMS6366_05 Datasheet, PDF (9/12 Pages) Fairchild Semiconductor – Selectable YPbPr HD/SD 4:2:2 Video Filter Driver

The Chroma filters are one half the bandwidth of the Luminance
filter therefore the propagation delay time through the Chroma
filter is longer than the Luminance filter. In the Standard Definition
(SD) case, the Chroma filter propagation delay is typically 60
nanoseconds longer than the Luminance filter. This is three
clock cycles at 54MHz so it is easily corrected by adding digital
delay as shown in Figure 18 and illustrated as a shift register in
Figure 17. In the High Definition (HD) setting the Chroma filter
propagation delay is typically 15ns longer than the Luminance
filter. This is one clock cycle at 74.25MHz so it is also easily
corrected by adding digital delay to the luminance path.
Video SoC
Video
Source
Digital
Delay
DAC
DAC
Y1
Pb, Pr
Figure 18. Digital Delay Compensation for 4:2:2
reconstruction filters
FMS6366 Rev. 2C
9
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