STV2246H STMicroelectronics, STV2246H Datasheet - Page 20

• Manufacturer Part Number: STV2246H
• Manufacturer: STMicroelectronics

Specifications of STV2246H

• Lead Free Status / Rohs Status: Compliant

3 FUNCTIONAL DESCRIPTION
The STV224XH/228XH is an integrated device
that processes PIF, SIF, Video and Chroma sig-
nals while scanning for PAL, SECAM and NTSC
standards. It includes a base band chroma delay
line, Video, SVHS and audio switches.
3.1 DETAILED FEATURES
3.1.1 Power Supplies
V
sors. GNDIF is the ground reference of these
parts.
V
digital parts. GNDD is the ground reference of
these parts.
V
ning part and the chroma decoder. GND 1 is the
ground reference of all these functions.
V
processing parts audio switch and internal CVBS
output. GND2 is the ground reference of these
parts.
3.1.2 Picture Intermediate Frequency (PIF)
– AGC amplifier.
– PLL synchronous demodulator. Bus-controlled
– Digital AFC via bus.
– IF Automatic Gain Control (AGC)
– Tuner-delayed AGC with bus control for AGC
– CVBS output with two bus-controlled ampli-
3.1.3 Sound Intermediate Frequency (SIF) and
Sound Demodulators
– QSS structure.
– SIF Automatic Gain Control (QSS mode).
CCIF
CCD
CC1
CC2
VCO for integrated tuning of the external LC res-
onator. For a 38.9 MHz VCO, the LC coil specifi-
cation has to be:
C = 39pF, f = 44 MHz ±2% (LC not connected).
For a 33.9 MHz VCO (L’), the VCO can be
switched via the bus control.
Negative modulation: top sync regulation, regu-
lation of overmodulated signals (overmodulation
regulation circuit enabled through bus control).
Positive modulation: main regulation on white
level with black level limitation.
gain and threshold. Tuner AGC output status can
be read in I²C bus read register.
tudes. CVBS output at 2 V
trap is not connected (QSS mode, for example).
CVBS output at 2.3 V
connected.
: 8 V power supply for video switches, scan-
: 8 V power supply for the luminance, RGB
: 5 V power supply dedicated to I²C bus and
: 5 V power supply dedicated to IF proces-
PP
if external sound trap is
PP
if external sound
STV224X, STV228X, STV223X - FUNCTIONAL DESCRIPTION
– Built-in sound bandpass.
– PLL FM Demodulator for 4.5, 5.5, 6.0 or 6.5 MHz
– The sound subcarrier level is valid when the FM
– Bus controls for FM de-emphasis (50 or 75 µs)
– AM demodulator.
– Sound demodulator output: either an AM or FM
– Sound subcarriers for the Stereo chassis.
3.1.4 Audio Switch
– One SCART switch.
– Bus-controlled volume and mute. Zero-crossing
– Automatic Volume Levelling (AVL) function can
– AVL status (Min. or Max. AVL Gain) can be read
– The AM sound can be selected on the main au-
3.1.5 Surface Acoustic Wave (SAW) Filter
Switch Control
– SAW filter switch control pin is available in the
3.1.6 Video Switches
– Video switch with three CVBS inputs and one
carriers. The Sound Standard is selected by the
MCU. The FM demodulator VCO is automatically
calibrated using the chroma crystal VCO refer-
ence frequency. The FM Demodulator VCO is
automatically calibrated for all sound standards
independently of the chroma crystal VCO fre-
quency, which is either 4.4 MHz or 3.5 MHz. For
each sound carrier frequency, the IC sends an
indication of the sound subcarrier level to the
MCU so that it can select the proper standard.
In Normal mode, the maximum FM deviation is
200 kHz. In Audio FM Wide mode (BGDKI), the
maximum FM deviation is 400 kHz. The Audio
FM Wide mode of the STV224XH must be used
in QSS applications only, using standard specific
SAW filters (DK SAW filter or BG SAW filter).
Demodulation VCO is calibrated. This informa-
tion can be read via the I²C Bus.
and FM deviation ±25 or ±50 kHz).
signal can be the output for the Mono chassis
function on volume control.
be enabled via the I²C bus.
in I²C bus register.
dio output for the Stereo chassis.
TQFP64 package. The SAW filter switch control
pin is used to select the correct SAW filter char-
acteristics (e.g.: M/N or BGDK characteristics).
In a multi-standard chassis, two output voltages
are selected via the I²C bus (low level voltage at
0.4 V Max., and high level voltage at 4 V Min.).
CVBS output (CVBSOUT1) which may be used
to drive a teletext decoder.
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