SDA9489X Datasheet, PDF (14/102 Pages) List of Unclassifed Manufacturers – PIP IV Advanced SOPHISTICUS High-End Picture-In-Picture ICs

SDA 9489X
SDA 9589X
Preliminary Data Sheet
System Description
by a digital PLL. At SECAM operation the PLL runs free and generates the line-wise
alternating subcarriers. A CORDIC structure demodulates the frequency-modulated UV
signals. The following SECAM de-emphasis filter characteristic is adjustable (DEEMP).
The chroma signal can be filtered before demodulation by means of a selectable IF-
prefilter (IFCOMP).
0
5
2.5
3.58
4.4
5
IFCOMP = ’00’
0
10
DEEMP = ’00’
IFCOMP = ’01’
2.5
DEEMP = ’01’
DEEMP = ’10’
5 ^{IFCOMP = ’10’}
15
DEEMP = ’11’
7.5
20
0
0.5
1
1.5
2
2.5
frequency [MHz]
10
2
3
4
5
6
frequency [MHz]
Figure 4-5 SECAM de-emphasis filter characteristic and IF-compensation filter
characteristic
The Hue Control (HUE) influences the phase of the demodulation subcarrier between
-44.8° and 43.4° in steps of 1.4°. This is provided for NTSC only and adjustment is
ineffective for PAL and SECAM signals.
The reference for the subcarrier generation is a crystal stable clock of 20.25000 MHz. In
order to avoid color standard detection problems, the maximum deviation of this
frequency should not exceed 100ppm. For a good PLL locking behavior a maximum
deviation of 40ppm is recommended. A small frequency adjustment (-150 ... +310 ppm)
is possible for using a crystal with small frequency deviations (SCADJ). For test
purposes, CPLL allows to open the loop of the chroma PLL.
For deviations in the chroma signal up to 30dB, a stable output amplitude after chroma
decoding is achieved due to the ACC (Automatic Chroma Control). If the chroma signal
(color burst) is below a selectable threshold (CKILL), the color will be switched off.
Alternatively the color-killer can be bypassed and the color can be switched on or off
under all conditions (COLON). By setting ACCFIX, the automatic chroma control is
disabled and set to a default value.
Micronas
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