Datasheet

75 W
S-VideoY'Out
CVBS
R
SOC/DAC/Encoder
S-Video Y’
R
S-Video C’
R
Y'/G'
R
1
2
3
4
5
6
7
8
9
10
20
19
18
17
16
15
14
13
12
11
SD1OUT
SD2OUT
SD3OUT
DisableSD
GND
Disable FHD
FHD1OUT
FHD2OUT
FHD3OUT
Bypass FHD
SD1IN
SD2IN
SD3IN
NC
V
S+
NC
FHD1IN
FHD2IN
FHD3IN
BypassSD
THS7364
Bypass
SDLPF
Bypass
LPFFHD
P' /B'
B
R
CVBS
P' /R'
R
R
75 W
75 W
S-VideoC'Out
75 W
75 W
75 W
Y'/G'Out
75 W
P' /B'Out
B
75 W
75 W
P' /R'Out
R
75 W
75 W
75 W
+2.7Vto
+5V
Disable FHD
DisableSD
THS7364
SBOS530 –AUGUST 2010 www.ti.com
TYPICAL CONFIGURATION AND VIDEO the definition of luminance as stipulated by the
TERMINOLOGY International Commission on Illumination (CIE). Video
departs from true luminance because a nonlinear
A typical application circuit using the THS7364 as a
term, gamma, is added to the true RGB signals to
video buffer is shown in Figure 77. It shows a DAC or
form R’G’B’ signals. These R’G’B’ signals are then
encoder driving the input channels of the THS7364.
used to mathematically create luma (Y’). Thus,
One channel is a CVBS connection while two other
luminance (Y) is not maintained, providing a
channels are for the S-Video Y’/C’ signals of an SD
difference in terminology.
video system. These signals can be NTSC, PAL, or
SECAM signals. The other three channels are the This rationale is also used for the chroma (C’) term.
component video Y’/P’
B
/P’
R
(sometimes labeled Chroma is derived from the nonlinear R’G’B’ terms
Y’U’V’ or incorrectly labeled Y’/C’
B
/C’
R
) signals. These and, thus, it is nonlinear. Chominance (C) is derived
signals are typically 480i, 576i, 480p, 576p, 720p, from linear RGB, giving the difference between
1080i, or up to 1080p60 signals. Because the filters chroma (C’) and chrominance (C). The color
can be bypassed, other formats such as R'G'B' video difference signals (P’
B
/P’
R
/U’/V’) are also referenced
up to QXGA or UWXGA can also be supported with in this manner to denote the nonlinear (gamma
the THS7364. corrected) signals.
Note that the Y’ term is used for the luma channels
throughout this document rather than the more
common luminance (Y) term. This usage accounts for
(1) Figure 77. Typical Six-Channel System Inputs from DC-Coupled Encoder/DAC with DC-Coupled Line
Driving
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