STV2246H STMicroelectronics, STV2246H Datasheet - Page 22

• Manufacturer Part Number: STV2246H
• Manufacturer: STMicroelectronics

Specifications of STV2246H

• Lead Free Status / Rohs Status: Compliant

olds, the OSD RGB signals are selected. When
the FBOSD voltage is greater than the second
threshold (4 V blanking threshold), the RGB out-
puts are blanked during the whole field, but not
during inserted cut-off lines (the cut-off loop is al-
ways active). The blanking feature, via the FBOSD
input pin, enables Vertical Oversize Blanking
when a 4:3 picture is displayed on a 16:9 screen in
Zoom mode. The picture outside the screen is
blanked by the Oversize Blanking pulse supplied
by the external vertical IC (STV9306).
3.2.7 Vertical Output
The Vertical output pulse is locked on a pulse that
is twice the horizontal frequency to ensure perfect
interlacing.
The Vertical output pulse duration is 10.5 lines.
Horizontal output pulse is a 28 µs line pulse on an
open collector output.
3.2.8 Vertical Control
Bus-controlled DC output voltage for adjusting the
vertical amplitude (pin VAMP). This voltage supply
is used to adjust the slope of the vertical sawtooth
generated by the external vertical booster.
Bus-controlled vertical position (pin VERT). The
high level of the vertical pulse is used to adjust the
vertical position.
The bus-controlled vertical output (pin VERT) low
level voltage can be either 0.2 V or 2.0 V.
3.2.9 Horizontal Output
Start-up circuit: the horizontal output is at high lev-
el (disabled) when V
and when V
Soft mode circuit: it provides a softer operating
horizontal output with a 75% duty cycle [t
(t
time (16 µs instead of 28 µs).
This mode is active at start-up until two frames af-
ter the V
active at shutdown when the V
6 V and 5.4 V. And finally, this mode is used if the
V
At shutdown, horizontal pulses are disabled when
V
3.5 V.
The horizontal output pulse may be disabled via
the bus (force a high level on HOUT).
The horizontal position adjustment is controlled via
the bus.
3.2.10 Horizontal Control
Safety input on BCL Pin. When the BCL Pin is
switched to ground, the horizontal output pulse is
disabled and the inhibition of horizontal output
HIGH
CC2
CC1
drops below 75% of the V
is less than 5.4 V or when V
+t
LOW
CC2
CCD
)]. This results in a smaller conducting
reaches 75% of the V
has not reached 4 V.
CC1
increases from 0 to 6.0 V
CC1
CC1
STV224X, STV228X, STV223X - FUNCTIONAL DESCRIPTION
CCD
.
floats between
CC1
is less than
. It is also
HIGH
/
pulse is maintained until V
(V
function can be disabled via the I²C bus. When
register 15hex data D7 is set to “1”, the Safety
function is reset and no longer active.
3.2.11 Combined Line Flyback / Super-
Sandcastle
Combined Line Flyback input and Super-Sandcas-
tle output: The line blanking level is clamped at
3 V, the burst key pulse voltage is 5 V and vertical
pulse voltage is 2 V. The line pulse is extracted
with a 2.5 V slicing level used for RGB line blank-
ing and PLL2 control.
3.2.12 Line Blanking
Line blanking at RGB outputs is logical OR of line
flyback pulse and internal line blanking pulse with
a 12 µs width.
In Wide Line Blanking mode, line blanking at RGB
outputs is logical OR of line flyback pulse and in-
ternal line blanking pulse with a 15.8 µs width.
Wide line blanking is recommended when display-
ing a 4:3 image on a 16:9 screen (horizontal scan-
ning reduction).
3.2.13 Copy Protection Mode
This mode is used to improve the display of copy-
protected video signals.
3.3 FILTERS
3.3.1 Integrated Trap Filter
Q = 1.5 (f-3dB = f0 (1-1/2Q)),
Center frequency:
– 4.43 MHz, 3.58 MHz for PAL and NTSC.
– 4.25 MHz, for SECAM
The chroma trap filter is switched off in SVHS
mode, or in color standard search mode (standard
not identified). In external YCrCb mode, the trap
and luma delay can be switched off via the I²C bus.
3.3.2 Integrated Chroma Bandpass
Q = 3.5, Center frequency: 4.43 MHz, 3.58 MHz.
The Bus Control Frequency Shift is used to opti-
mize the chroma response for the video signal
from the IF stage.
3.3.3 Integrated Bell Filter for SECAM
Q = 16, Center frequency: 4.286 MHz.
The Bus Control Frequency Shift is used to opti-
mize the chroma response for the video signal
from the IF stage.
(-20 dB rejection between 4.1 MHz and
4.4 MHz).
CC1
power supply is switched off). The Safety
CC1
is less than 3 V
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