STV2118B
BUS CONTROLLED PAL/SECAM/NTSC TV PROCESSOR
June 1996
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GND1
Y/CVBS
BEXT
FBOSD
ROS D
GOSD
BOS D
S WI
VOL
FTUN2
FTUN1
S CL
SDA
ACC
CLPF
CXTL1
CXTL2
GND2
V
C C2
BYO
RYO
LFB/S C
HOUT
VOUT
VAMP
S LPF
S XTL
BCL
ICAT
RO
GO
BO
CR
CB
CG
CHR/SVHS
V
C C1
CHROMA/SCANNING/BUS SUP P LY
BYI
RYI
B-Y OUTPUT
R-Y OUTP UT
R-Y INPUT
B-Y INPUT
LINE FLYBACK INPUT/SANDCASTLE OUTP UT
HORIZONTAL OUTP UT
VERTICAL OUTP UT
AMPLITUDE CONTROL VOLTAGE
S CANNING LOOP FILTER
503kHz CERAMIC
BEAM CURRENT LIMITER
CATHODE CURRENT MEASUREMENT
RED OUTP UT
GREEN OUTPUT
BLUE OUTP UT
RED CUT-OFF CAPACITOR
BLUE CUT-OFF CAPACITOR
GREEN CUT-OFF CAPACITOR
CHROMINANCE INPUT/SVHS SELECTION
VIDEO S UP PLY
BUS /VIDEO GROUND
CVBS OR LUMINANCE INPUT
EXTERNAL BLUE INPUT
OS D RGB INSERTION
OS D BLUE INPUT
IF STANDARD AND S WITCH S ELECTION
VOLUME AND MUTE CONTROL VOLTAGE
FILTER TUNING
DATA WIRE I
2
C BUS
ACC CONTROL CAPACITOR
CHROMA LOOP FILTER
3.58 MHz XTAL
CHROMA/SCANNING GROUND
4.43 MHz XTAL
CLOCK WIRE I
2
C BUS
CLOCHE FILTER TUNING
OS D GREEN INPUT
OS D RED INPUT
GEXT
REXT
FBEXT
EXTERNAL GREEN INPUT
EXTERNAL RED INPUT
EXTERNAL RGB INSERTION
2118B-01.EPS
PIN CONNECTIONS
SHRINK42
(Plastic Package)
ORDER CODE : STV2118B
.
I
2
C BUS CONTROL OF ALL FUNCTIONS
.
INTEGRATED FILTERS
(TRAP, BANDPASS, CLOCHE)
.
INTEGRATED LUMINANCE DELAY LINE
.
PAL/SECAM/NTSC CHROMA DEMODULATORS
.
AUTOMATIC CUT-OFF CURRENT LOOP
.
TWO RGB INPUTS
.
SVHS SWITCH
.
TWO PLLs HORIZONTAL DEFLECTION
.
VERTICAL COUNT DOWN
.
VERY FEW EXTERNAL COMPONENTS
DESCRIPTION
The STV2118B is a fully bus controlled IC for TV
luma, chroma and deflection processing.
Used with STV8224 (PIF/SIF/switches), TDA1771
or TDA8174 (frame booster), STV2180(delay line),
i t al l ows t o des ig n a PAL/ SEC AM/ NT SC
(BGDKILMN) set with very few external compo-
nents and no adjustment.
1/25
Y
CHR
FB
R
G
B
FB
R
G
B
Y/CVBS
CHR
ACC
C XTAL2
C XTAL1
R
G
B
ICAT
C R
CG
CB
BCL
VOUT
HOUT
S XTAL SLPF
LFB/SC
GND2
S WI
VOL
CLP F
R -Y
B-Y
FILTER
TUNING
V
CC1
S DA
S C L
CLOCHE
TUNING
SHARP
V
CC2
GND1
FILTER TUNING
TRAP BANDP ASS
CLOCHE
S VHS S WITCH
20
23
8
9
DE LAY
LINE
SHARP NE S S
MATRIX
S ATURATION
BR IGHTNE SS
CONTRAS T
RGB SWITCHES
C ontras t
BLANKING
AUTO CUT-O FF
BLACK & WHITE
CONTR OL
22
42
19
18
17
16
39
38
R-Y
B-Y
EXTERNAL
OS D
15
14
13
12
29
28
27
30
26
24
25
31
35
VAMP
34
FRAME
S CANNING
LINE
S CANNING
36
21
1
37
33
32
S YNC
S EPARATOR
STANDARD
IDENTIFICATION
ACC
5
P AL/
NTS C
KILLER
S ECAM
KILLER
S ECAM
DE MODULATOR S
PAL/NTSC
DE MODULATOR S
DELAY LINE INTERFACE
2
3
4
40
41
BUS
DECODER
6
7
11
10
HUE
BRIG
SAT
CONT
STD
DRIVE
VIDEO
IDENTIFICATION
CUT-OFF
S TV211 8B
PLL
2118B-02.EPS
BLOCK DIAGRAM
STV2118B
2/25
FUNCTIONAL DESCRIPTION
1 - DEFLECTION CIRCUIT
Note : [X,Y] : line number referred to the internal
line counter numbering
- Fully integrated synch. separator, with a low pass
filter, a black level alignment of the Y/CVBS input,
a slicing level at 2/3,1/3 of the sync. pulse ampli-
tude.
- Frame sync. pulse locked on 2 f
H
frequency to
perfect interlace.
- 500kHz VCO with an external ceramic resonator.
- Two phase locked loops
the first PLL locks the VCO on the video signal
frequency,
the second PLL compensates the line transistor
storage time.
- Three time constants for the first PLL.
the long time constant is used for normal opera-
tion
the short time constant is automatically used
during the frame retrace and in search mode of
VCR when the frame pulse is outside [258,264]
and [309,314].
very long time constant when no video recogni-
tion
Time constants in normal operation
(automatic selection of time constants) :
50Hz input signal :
- short time constant : [306, 21]
- long time constant : the rest of the field
60Hz input signal :
- short time constant : [0, 16]
- long time constant : the rest of the field
inhibition of the first PLL :
the first locked loop is opened from line 309 to
line 4.5 (or 314) in 50Hz mode. It is opened from
line 258 to line 5.5 (or 264) in 60Hz mode.
the time constants values are chosen by means
of external components.
possibility to force the short time constant
through the bus.
possibility to force the very long time constant
through the bus.
- Video identification : coincidence detector be-
tween the line synchro top and a line frequency
window from the first PLL. The video identification
status is available in the output register of the I
2
C
bus decoder.
- Generation of burst gate pulses and line fre-
quency signals from the first PLL to drive the
chroma and video circuits. The burst gate pulse
is also sent to the sandcastle generator.
- Frame synchro window :
[248, 352]
catching
- Field frequency selection windows :
[248, 288]
60 Hz mode selec tion i f two
consecutive frame pulses occur
inside this window,otherwise 50Hz
mode selection.
[288, 352]
50Hz mode selection window
- frame blanking pulse :
from line 0 to 21 in 50Hz mode
from line 0 to 16 in 60Hz mode
- Vertical output pulse is 10.5 lines long.
- Horizontal output pulse : 28
s line pulse on an
open collector output;
- Start up circuit : the horizontal output is at a high
level when V
CC
increases from 0 to 6.8V. On
shutting down, horizontal pulses are disabled
when V
CC
is below 6.2V.
- Soft-start circuit : the duty cycle of the horizontal
output is 78 % (Thigh/(Thigh + TLow)) when V
CC1
is lower than (0.75 x V
CC2
), during the rising
time.
During the falling time, a 78% duty cycle HOUT
pulse is provided when V
CC1
is lower than
(0.60 x V
CC2
).
- Possibility to disable the horizontal output pulse
through the bus (force a high level on HOUT).
- Horizontal position adjustment controlled by bus.
- Bus controlled output voltage to adjust the vertical
amplitude; this voltage permits to adjust the slope
of the vertical sawtooth generated by the external
frame booster.
- Bus controlled vertical position ; the high level of
the vertical pulse permits to adjust the vertical
position.
- Bus controlled 4/3-16/9 selection : the low level
of the vertical pulse is 0.1V when 16/9 is selected,
2V when 4/3 is selected.
- Combined flyback input and sandcastle output
(Pin 37).
Two thresholds on LFB/SCO Pin : The lowest
threshold (0.7V) permits to extract the line blank-
ing pulse; the highest threshold (2V) permits to
extract the line pulse for PLL2.
The sandcastle signal at Pin 37 is used to control
the external baseband chroma delay line.
STV2118B
3/25
FUNCTIONAL DESCRIPTION (continued)
2 - FILTERS
- Integrated trap filter :
Q
=
1
f
o
f
-
3dB
-
f
-
3dB
f
o
Q = 1.7 at sharp. min
Q = 3.0 at sharp. max
Center frequency : - 4.43MHz,
3.58MHz for PAL, NTSC
- 4.25MHz, for SECAM
(f
-3dB
= 3 M Hz ; -2 0 dB
rejection between 4.1MHz
and 4.4MHz)
- Integrated chroma bandpass :
Q = 3.5
Center frequency : 4.43MHz, 3.58MHz
- Integrated cloche filter for SECAM :
Q = 16
Center frequency : 4.286MHz
- Integrated delay line :
Bandwidth = 8MHz
- Integrated low pass filter for deflection part.
- All filters are tuned with a reference phase locked
loop.
The PLL consists of a lowpass filter, a phase
comparator, a loop filter (an external capacitor).
The reference signal is the continuous carrier
wave from the VCO (4.43MHz or 3.58MHz). The
PLL adjusts the center frequency of the lowpass
so that it is equal to the reference signal. The
tuning voltage of the PLL is used to adjust all other
filters. The cloche filter is fine tuned with a second
PLL operating during frame retrace.
3 - VIDEO CIRCUIT
- 2 RGB inputs : RGB (OSD) input has priority
against the RGBext. Maximum contrast on RGB
(OSD). -12dB range contrast control on RGBext.
Possibility to disable the RGBext insertion
through the bus.
- Oversize blanking capability on FB(OSD)(Pin15)
input. The RGB ouputs will be blanked when the
voltage on Pin 15 will exceed the second thresh-
old at 1.9V (blanking threshold) : the whole field
is blanked but not the inserted cut-off pulses. The
OSD insertion threshold is 0.7V.
- Automatic cut-off current loop : 2V cut-off range.
Sequential cut-off current measurement during
the three lines after the frame blanking signal.
Leakage current measurement during the frame
blanking, memorization on an internal capacitor.
- Possibility to force through the bus the inserted
cut-off pulses on lines 23/24/25(CCIR) in 50Hz
and 60Hz mode.
- Warm up detector.
- Beam current limiter DC voltage input.
The beam current limiter control voltage will act
on contrast first, then the brightness will be de-
creased when contrast attenuationreaches -5dB.
- Bus control of the red, green and blue channel
gain (White point adjustment)
- Bus control of the red and green DC levels (black
point adjustment)
- PAL and SECAM matrix, specific NTSC matrix
when demodulation angles are (0
o
, 104
o
).
- Switch-off of the trap filter in SVHS mode.
- Bus controlled contrast on luminance
(20dB range)
- Bus controlled saturation (50dB range)
- Bus controlled brightness : 40% range at maxi-
mum contrast.
- Bus controlled sharpness (peaking) ; sharpness
active in PAL/NTSC standard only.
- Noise coring function on sharpness.
STV2118B
4/25
FUNCTIONAL DESCRIPTION (continued)
4 - CHROMA CIRCUIT
4.1 - PAL/SECAM/NTSC Decoders
- SVHS inputs ; bus controlled SVHS mode.
- 30dB range ACC
- Use of an external base band delay line
(STV2180 recommended)
- Automatic standard identification, with possibility
to force the standard through the bus.
4.2 - PAL/NTSC Decoders
- ACC done by peak detector on synchronous de-
modulation of the burst
- Fully integrated killer functions.
- VCO using two standard crystals : 4.43MHz and
3.58MHz. One crystal is internally selected de-
pending on the standard selection.
XTAL SPECIFICATION :
Frequency :
4.433619MHz (PAL/SECAM)
3.579545MHz (NTSC M)
3.575611MHz (PAL M)
3.582056MHz (PAL N)
Vibration mode : Fondamental, series resonance
(no serial capacitor)
Motional capacity : 13fF
3fF
Resonance resistance : < 70
Shunt capacitance : < 7pF
Spurious response : No resonance at 3*f
o
3kHz
- 0
o
and
90
o
demodulation angles for PAL
- (0
o
, 90
o
) or (0
o
,104
o
) = demodulation angles for
NTSC. The selection of 90
o
or 104
o
is made
through the bus.
- Bus control Hue adjustment in NTSC mode.
4.3 - SECAM Decoder
- ACC
- Fully integrated killer
- Two integrated discriminators with two PLL
- Integrated deemphasis
4.4 - Standard Identification
- Sequential identification.
- 3 identification sequences : XTAL1 (4.43MHz)
mode to identify either PAL or NTSC, XTAL2
(3.58MHz) mode to identify either PAL or NTSC,
SECAM mode (XTAL1 selection).
- PAL/NTSC priority
- the SECAM mode is locked after two identified
SECAM sequences
- the SECAM mode can be selected in 50Hz only
- Blanking of the (R-Y) and B-Y) outputs during
color search mode.
5 - OTHER FUNCTIONS : IF CONTROLS
5.1 - Volume Control and Mute
The volume control voltage range on Pin 10 is from
0.5V to 5V. A low voltage on Pin 10 (below 0.2V)
will mute the FM demodulator of the IF circuit
STV8224. It will put the volume at the minimum
level and thus there will be no sound either in TV
mode or SCART mode.
The volume control voltage and the mute level are
controlled by the bus.
5.2 - IF Standard and TV/SCART Mode Selection
The selection of IF standard (positive or negative
vision modulation) and theTV/SCART mode is con-
trolled by the bus. The selection is converted in four
voltages on Pin 21.
The lowest voltage selects the TV mode and the
NEGATIVE vision modulation.
The highest voltage (open collector output with
internal pull-up resistor to V
CC
) selects the SCART
mode and the NEGATIVE vision modulation.
The two other intermediate voltages select either
TV mode and POSITIVE vision modulation or
SCART mode and POSITIVE vision modulation.
STV2118B
5/25
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