TDA9550 PHILIPS [NXP Semiconductors], TDA9550 Datasheet - Page 105

• Manufacturer Part Number: TDA9550
• Description: TV signal processor-Teletext decoder with embedded m-Controller
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
63. The control circuit contains a Peak White Limiting (PWL) circuit and a soft clipper.
64. The soft clipper gain reduction is measured by applying a sawtooth signal with rising slope and 0.7 V
Table 147 Some examples for the FM-PLL filter
Table 148 Output current of the phase detector in the various conditions
Note
1. Gating is active during vertical retrace, the width is 22 s. This gating prevents disturbance due to Macro Vision Anti
2. Gating is continuously active and is 5.7 s wide
2000 Jun 22
TV signal processor-Teletext decoder with
embedded -Controller
VID
a) The detection level of the PWL is adjustable via the I
b) In addition to the PWL circuit the IC contains a soft clipper function which limits the high frequency signals when
CVBS input. To prevent the beam current limiter from operating a DC voltage of 3.5V must be applied to BCLIN pin.
The contrast is set at the maximum value, the PWL (peak white limiting) level at the minimum value, and the soft
clipping level is set at 0% above the PWL level (SOC
RGB outputs is now determined at begin and end of the sawtooth. The soft clipper gain reduction is defined as the
ratio of the slopes of the tangents for black and white, see Fig.47.
Copy signals.
0
BL
0.85 V
contrast setting). The high frequency components of the video signal are suppressed so that they do not activate
the limiting action. The contrast reduction of the PWL is obtained by discharging the capacitor of the beam current
limiting input.
they exceed the peak white limiting level. The difference between the peak white limiting level and the soft clipping
level is adjustable via the I
higher than the PWL level). It is also possible to switch-off the soft clipping function.
3dB
100
160
I
2
C-BUS COMMANDS
(kHz)
POC
BL-WH
0
0
0
0
0
0
0
0
1
(this amplitude is related to the CVBS/Y input signal (typical amplitude 1.0 V
FOA
0
0
0
0
0
1
1
1
C
2
C-bus and can be varied between 0 and 10% in 3 steps (soft clipping level equal or
S
4.7
4.7
FOB
(nF)
0
0
0
1
1
0
0
1
yes
yes
yes
yes
yes
yes
yes
IFI
no
IC CONDITIONS
10
105
yes
yes
yes
yes
yes
C
SL
no
no
=00). The tangents of the sawtooth waveform at one of the
P
820
330
2
C-bus and has a control range between 0.55 and
(nF)
NOISE
yes
yes
no
no
TDA955X/6X/8X PS/N1 series
SCAN
200
200
200
200
200
30
30
30
6
R (k )
2.7
3.9
-1 CURRENT/MODE
V-RETR
Tentative Device Specification
300
300
300
300
300
30
30
30
6
BL-WH
GATING
yes
yes
yes
yes
yes
yes
no
no
no
) at maximum
(2)
(2)
(2)
(2)
(1)
(1)
BL-WH
0.5
0.5
slow/fast
slow/fast
normal
normal
normal
MODE
at the
OSD
slow
slow
fast
off