TMC22053KHC Fairchild Semiconductor, TMC22053KHC Datasheet - Page 43

• 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

PRODUCT SPECIFICATION
TMC22x5y Functional Description
Input Processor
The input processor selects between the two external video
sources on VIDEO A and VIDEO B. If the TRS stripper or
GRS stacker is active, then the user must select the input
with either the GRS (in genlock mode) or with the embedded
TRS words as output VA. If the input data are separate luma
and chroma or Y and C
programmed to put the chrominance or C
VB and the luminance or Y onto VA.
To ensure that the chrominance data or the C
two’s complement arithmetic format, the register bit MSBI
inverts the msb of the DB input. For composite inputs, the
IPCMSB register bit should be set LOW, as the ABMUX
register bit is used to select the input(s) to the comb filter.
Bandsplit Filter (BSF)
In its simple mode of operation, the TMC22x5y uses a com-
plementary bandsplit filter, instead of a notch filter for the
luma and a bandpass for the chroma. The notch and band-
pass filter technique, removes frequency bands from the
composite video spectrum which can never be retrieved.
The complementary bandsplit filter technique, shown in
Figure 12, allows the decoded component video signals to be
re-encoded into a composite video signal with the minimum
of losses to the composite video spectrum.
VideoA
VideoB
2:2 MUX
B
C
msb
R
x
data the input processor must be
VA
VB
IPMUX
Input Processor Control Register
B
C
IP8B
R
B
C
onto output
GRS Stacker (TMC22071)
R
TRS Stripper (D1/D2/D3)
Figure 11. Input Processor
data are in
TDEN
and
TBLK
The complementary bandsplit filter separates the base band
composite video into two bands by passing it through a low
pass filter and subtracting the low pass (luma) data from the
composite video to produce the high pass (chroma) data. As
the base bandwidths and subcarrier frequencies of the differ-
ent NTSC and PAL video formats are so different, and the
decoder has to be capable of working over a large frequency
range, it is necessary to provide two low pass filters. These
filters are selectable by the BSFSEL register bit and are inde-
pendent of the video standard. A comparison of the different
data rates to normalized subcarrier frequencies is provided in
Table 2.
The complementary bandsplit low pass frequency response
is shown in Figure 13 and Figure 14.
Input
ICPMSB ABMUX CKSEL
Invert
MSB
Figure 12. Complementary Bandsplit Filter
DA
DB
LPF
lsb
2:2 MUX
–
Primary Data
to Comb Filter
Secondary Data
to Comb Filter
HPF Output
65-22x5y-52
LPF Output
65-22x5y-53
TMC22x5y
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