TDA8366 Philips Semiconductors, TDA8366 Datasheet - Page 10

• Manufacturer Part Number: TDA8366
• Description: I2C-bus controlled PAL/NTSC TV processor
• Manufacturer: Philips Semiconductors

Philips Semiconductors
output for the vertical drive signal and a single-ended
output for the EW drive. Both the vertical drive and the EW
drive outputs can be modulated for EHT compensation.
The EHT compensation pin is also used for overvoltage
protection.
The geometry processor also offers the possibilities for
vertical compression (for display of 16 : 9 pictures on a
4 : 3 screen) and vertical expansion (for display of
4 : 3 pictures on a 16 : 9 screen with full picture width, or
for display of ‘letter-box’ transmissions on a 4 : 3 screen
with full picture height). For the expand mode it is possible
to shift the picture vertically (only one fixed position).
Also the de-interlace of the vertical output can be set via
the I
To avoid damage of the picture tube when the vertical
deflection fails the guard output current of the TDA8350
can be supplied to the sandcastle output. When a failure is
detected the RGB-outputs are blanked and a bit is set
(NDF) in the status byte of the I
deflection output stage is connected this guard circuit will
also blank the output signals. This can be overruled by
means of the EVG bit of subaddress 0A (see Table 1).
Integrated video filters
The circuit contains a chrominance bandpass and trap
circuit. The chrominance trap filter in the luminance path is
designed for a symmetrical step response behaviour. The
filters are realized by means of gyrator circuits and they
are automatically tuned by comparing the tuning frequency
with the crystal frequency of the decoder. The luminance
delay line and the delay for the peaking circuit are also
realized by means of gyrator circuits.
It is possible to connect a Colour Transient Improvement
(CTI) or Picture Signal Improvement (PSI) IC to the
TDA8366. Therefore the luminance signal which has
passed the filter and delay line circuit is externally
available. The output signal of the transient improvement
circuit must be supplied to the luminance input circuit.
When the CTI function is not required the two pins must be
AC-coupled.
January 1995
I
processor
2
2
C-bus controlled PAL/NTSC TV
C-bus.
2
C-bus. When no vertical
10
Video switches
The circuit has two CVBS inputs and an Super-Video
Home System (S-VHS) input. The input can be chosen by
the I
CVBS
S-VHS input. When the input selector is in this position it
switches to the S-VHS input if the S-VHS detector detects
sync pulses on the S-VHS luminance input. The S-VHS
detector output can be read by the I
S-VHS option is not used the luminance input can be used
as a second input for external CVBS signals. The choice is
made via the CVS-bit (see Table 1).
The video switch circuit has two outputs which can be
programmed in a different way. The input signal for the
decoder is also available on the TXT output. Therefore this
signal can be used to drive the teletext decoder and the
SECAM add-on decoder. The signal on the PIP output can
be chosen independent of the TXT output. If S-VHS is
selected for one of the outputs the luminance and
chrominance signals are added so that a CVBS signal is
obtained again.
Colour decoder
The colour decoder contains an alignment-free crystal
oscillator, a killer circuit and the colour difference
demodulators. The 90 phase shift for the reference signal
is made internally. The demodulation angle and gain ratio
for the colour difference signals for PAL and NTSC are
adapted to the standard.
The colour decoder is very flexible. Together with the
SECAM decoder TDA8395 an automatic multistandard
decoder can be designed.
Which standard the IC can decode depends on the
external crystals. If a 4.4 MHz and a 3.5 MHz crystal are
used PAL 4.4, NTSC 4.4, NTSC 3.5 and PAL 3.5 can be
decoded. If two 3.5 MHz crystals are used PAL N and M
can be decoded. If one crystal is connected only
PAL/NTSC 4.4 or PAL/NTSC 3.5 can be decoded. The
crystal frequency of the decoder is used to tune the line
oscillator. Therefore the value of the crystal frequency
must be given to the IC via the I
2
C-bus. The input selector also has a position in which
EXT
is processed, unless there is a signal on the
2
C-bus.
Objective specification
2
C-bus. When the
TDA8366