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TDA4687 Datasheet, PDF (17/24 Pages) NXP Semiconductors – Video processor with automatic cut-off control | |||
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Philips Semiconductors
Video processor with automatic cut-off control
Product speciï¬cation
TDA4687
Table 3 Demodulator axes and ampliï¬cation factors
PARAMETER
(B â Y)* demodulator axis
(R â Y)* demodulator axis
(R â Y)* ampliï¬cation factor
(B â Y)* ampliï¬cation factor
NTSC
PAL
0°
0°
115°
90°
1.97
1.14
2.03
2.03
Table 4 PAL/SECAM and NTSC matrix; note 1
MATRIX
PAL/SECAM
NTSC
NMEN
0
1
Note
1. PAL/SECAM signals are matrixed by the equation: VG â Y = â0.51VR â Y â 0.19VB â Y
NTSC signals are matrixed by the equations (hue phase shift of â5 degrees):
VR â Y* = 1.57VR â Y â 0.41VB â Y; VG â Y* = â0.43VR â Y â 0.11VB â Y; VB â Y* = VB â Y
In the matrix equations: VR â Y and VB â Y are conventional PAL demodulation axes and amplitudes at the output of
the NTSC demodulator. VG â Y*, VR â Y* and VB â Y* are the NTSC modified colour difference signals; this is equivalent
to the demodulator axes and amplification factors shown in Table 3. VG â Y* = â0.27VR â Y* â 0.22VB â Y*.
handbook, full pagewidth
(1)
(2)
cut-off measurement line
for red signal
(1) Maximum brightness.
(2) Nominal brightness.
Fig.6 Cut-off measurement pulse.
MHA697
ultra-black
1997 Jun 23
17
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