STV2246H STMicroelectronics, STV2246H Datasheet - Page 21

• Manufacturer Part Number: STV2246H
• Manufacturer: STMicroelectronics

Specifications of STV2246H

• Lead Free Status / Rohs Status: Compliant

STV224X, STV228X, STV223X - FUNCTIONAL DESCRIPTION
– A second CVBS output (CVBSOUT2) is able to
– SVHS switch, Y input is combined with CVBS 3
3.2 DEFLECTION PART
3.2.1 Synchronization Separator
– Fully-integrated synchronization separator with a
3.2.2 Two Phase-Locked Loops (PLL)
Auto-calibrated VCO using the chroma crystal ref-
erence. Crystal control pin X1/VAMP/CHROUT in-
dicates the crystal reference value on Pin XTAL1.
When a 4.43 MHz crystal is connected to
Pin XTAL1, the output load on Pin X1/VAMP/
CHROUT must be greater than 80 kΩ. When a
3.58 MHz crystal is connected to Pin XTAL1, the
output load must be less than 10 kΩ.
The first PLL locks the VCO to the video line fre-
quency and the second PLL compensates the line
transistor storage time.
Three time constants for the first PLL.
– [X,Y]: Line number referring to the internal line
The long time constant is used for normal opera-
tion.
The short time constant is automatically used dur-
ing the VCR search mode and frame retrace when
the frame pulse is outside [258,264] and
[309,314].
The very long time constant is used when there is
no video recognition (very good OSD stability).
Time constants in normal operation (automatic se-
lection of time constants):
21/86
output recombined Y+C signals.
All switches are independently controlled.
input. CVBS/SVHS modes can be selected ei-
ther by bus control (software selection), or by
sensing the DC voltage on the Chroma Input pin
(hardware selection). If the Chroma Input is
grounded, the CVBS mode is selected and the
bus control is not active. If the DC level of the
Chroma Input is higher than the SVHS threshold,
then the bus control for the SVHS switch is ac-
tive. Therefore, the SVHS mode can be selected
by hardware using a special SVHS connector
that includes a mechanical switch. In this type of
application, the bus control is set to SVHS mode,
and the CVBS mode is selected by grounding the
Chroma Input pin.
low pass filter, black level alignment of the CVBS
input, and a 50% slicing level for the synchro-
nized pulse amplitude.
counter numbering system.
– 50 Hz input signal:
– 60 Hz input signal:
3.2.2.1 Inhibition of the First PLL
The first PLL is inhibited from line 309 to line 4.5
(or 314) in 50 Hz mode and from line 258 to line
5.5 (or 264) in 60 Hz mode. The time constant val-
ues are chosen by means of external components.
– Possibility of forcing the short time constant dur-
– Possibility of forcing the long time constant dur-
– Possibility of forcing a very long time constant
Generation of burst gate pulses and line frequency
signals from the first PLL to drive the Chroma and
Video circuits. The burst gate pulse is also sent to
the super-sandcastle generator.
3.2.3 Video Identification
The video identification status is available in the
output register of the I²C bus decoder (independ-
ent from PLL1).
3.2.4 Vertical Synchronization
Frame synchronized window:
– large window: [248,352] in AUTO mode,
– narrow window: [309,314] in 50 Hz mode,
Field frequency selection windows:
– [248,284] 60 Hz mode selection window.
– [288,352] 50 Hz mode selection window.
Frame blanking pulse adapted to standard:
– from line 309 to line 21 in 50 Hz mode,
– from line 258 to line 16 in 60 Hz mode.
3.2.5 Vertical Blanking
Long blanking mode: the end of frame blanking is
line 21 both in 50 and 60 Hz modes. This mode is
useful when the flyback time of the vertical output
stage is longer than the 60 Hz blanking time. It is
used to optimize the 50/60 Hz vertical amplifier ap-
plication due to long frame blanking.
3.2.6 Vertical Oversize Blanking
The Oversized Blanking function is controlled by
the voltage on the FBOSD pin. When the FBOSD
voltage is between the first and the second thresh-
short time constant: [306,21],
long time constant: the rest of the field.
short time constant: [0,16],
long time constant: the rest of the field.
ing the all frame via the bus.
ing the all frame via the bus.
during the all frame via the bus.
[248,284] in forced 60 Hz mode, [288,352] in
forced 50 Hz mode.
[258,264] in 60 Hz mode.