SERVICE MANUAL
of coring according to the video level with the
video dependent coring. The TDA9178 is also
capable to give extra sharpness in the cases
of saturated red and magenta parts of the
screen using the color dependent sharpness
feature.
An embedded noise detector measures noise
during the field retrace in parts which are
expected to be free from video or text
information. With the noise detector a variety
of ‘smart noise control’ architectures can be
set up.
A feature mode detector is available for
detecting signal sources like VCR (in still
picture mode) that re-insert the levels of the
retrace part. For this kind of signals the noise
measurement of the TDA9178 is not reliable.
An output signal (on the I
2
C-bus and on a
separate pin) is available that detects when
the picture content has been changed
significantly, called cue flash.
An embedded 6-bit ADC can be used for
interfacing three analog low frequency voltage
signals (e.g. ambient light control or beam
current voltage level) to the I
2
C-bus.
In the demonstration mode all the features
selected by the user are automatically toggled
between on and off.
The TDA9178 concept has a maximum
flexibility which can be controlled by the
embedded I
2
C-bus. The supply voltage is 8 V.
The device is mounted in a 24-lead SDIP
package, or in a 24-lead SO package.
Table 11 Pinning
symbol Pin
Description
SC 1
Sandcastle input
n.c. 2
Not connected
ADEXT1 3
ADC input 1
ADEXT2 4
ADC input 2
ADEXT3 5
ADC input 3
YIN 6
Luminance input
ADR 7
Address selection input
UIN 8
U signal input
VIN 9
V signal input
TP 10
Test pin
SCL 11
Serial clock input (I
2
C-bus)
n.c. 12
Not connected
n.c. 13
Not connected
SDA 14
Serial data input/output (I
2
C-bus)
DEC
DIG
15
Decoupling digital supply
VOUT 16
V signal output
UOUT 17
U signal output
V
EE
18
Ground
YOUT 19
Luminance output
V
CC
20
Supply voltage
SOUT 21
SCAVEM output
CF 22
Cue flash output
n.c. 23
Not connected
n.c. 24
Not connected
Fig. 30 Pin Configuration (SOT137-1).
37
