TMC22053KHC Fairchild Semiconductor, TMC22053KHC Datasheet - Page 42

• Manufacturer Part Number: TMC22053KHC
• Manufacturer: Fairchild Semiconductor

Specifications of TMC22053KHC

• Screening Level: Commercial
• Package Type: MQFP
• Pin Count: 100
• Lead Free Status / RoHS Status: Compliant

TMC22x5y
The TMC22x5y Comb Filter
Architecture
The TMC22x5y, when implementing a line based comb
filter, has a core architecture as shown in Figure 10. The con-
cept of the complementary bandsplit filter is also observed in
the complementary comb filter architecture. It is therefore
possible to adapt between the complementary comb filter
and bandsplit filter without throwing away any of the
original composite video frequency spectrum.
The first step in the complementary comb filter is to separate
the high frequency luminance from the chrominance signal.
This combed high frequency luma signal is shown as
YCOMB in Figure 10. The second step is to produce an array
of comb filter error signals that indicate the degree of confi-
dence that the YCOMB signal is just the high frequency luma
and not a combination of high frequency luma and chroma
smeared over the number of lines used in the comb filter. The
signal representing this degree of confidence is termed “K”
42
Input
1H
1H
Figure 10. TMC22x5y Line Based Comb Filter Architecture
Bandsplit
Filters
XLUT
COMB
Filter
in Figure 10. The last step is to provide a complementary
cross fade between the YCOMB signal and the output of the
complementary bandsplit filter, shown as SIMPLE in Figure
10. The FLAT signal is simply a delayed version of the input
to the comb filter, therefore the sum of Output1 and Output2
will always be equal to the FLAT video input.
The TMC22x53 comb filter architecture has three taps.
These taps are three consecutive field lines in a line based
comb, three consecutive picture lines in a field based comb,
or lines that are one frame and one field line apart in the
frame based comb. In addition to these different inputs to the
comb filter, NTSC and PAL video signals comb over differ-
ent taps in different architectures, as described in the comb
filter introduction.
The total internal pipeline latency is 1H + 38 pixels for 3 line
comb filters, for all other comb filter and simple decoder
architectures the pipeline latency is 38 pixels.
XLUT
SIMPLE
YCOMB
K
X
Simple +/- {k * Ycomb}
+
–
PRODUCT SPECIFICATION
Output1
Output2