THS8134_14 Datasheet, PDF (20/26 Pages) Texas Instruments – TRIPLE 8-BIT, 80 MSPS VIDEO D/A CONVERTER

THS8134, THS8134A, THS8134B
TRIPLE 8ĆBIT, 80 MSPS VIDEO D/A CONVERTER
WITH TRIĆLEVEL SYNC GENERATION
SLVS205D − MAY 1999 − REVISED MARCH 2000
APPLICATION INFORMATION
SMPTE 274M (continued)
In the YPbPr mode of this standard, the sync is centered around the center span of the video amplitude levels,
as shown in Figure 14. So the current for Pb and Pr is down-shifted with respect to Y to accommodate the
minimum data level at 0 mA. Thus, an input code of 00h corresponds now to an output drive of 0 mA while the
negative sync level is at 1.33 mA, corresponding to 50 mV. The Pb and Pr data input format is offset binary.
Table 10 lists the THS8134 full-scale output currents for Pb and Pr channels in the YPbPr operation mode of
the device. The operation mode corresponds to YPbPr with sync-on-all of Table 1.
Table 10. THS8134 Signals for SMPTE 274M Compliant Operation on Pb and Pr Channels
LEVEL
Max
Video
Sync Pos
Blank
Sync Neg
Min
Pb, Pr
(mA)
(V)
18.67
0.7000
Video
Video
17.33
0.650
9.33
0.350
1.33
0.050
0
0
SYNC
1
1
0
1
0
1
SYNC_T
X
X
1
X
0
X
BLANK
1
1
X
0
x
1
DAC INPUT
FFh
Data
xxh
xxh
xxh
00h
SMPTE 296M
This standard defines a raster scanning format of 1280x720 and an aspect ratio of 16:9, the analog and digital
representation, and the definition of an analog interface. Both GBR and YPbPr component color encoding can
be used.
With respect to the sync and video level definition, this standard is analogous to SMPTE 274M with the use of
a tri-level sync pulse. Therefore, for the generation of output signals compliant to this standard, refer to the
configuration of THS8134 for SMPTE 274M.
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