SGS Thomson Microelectronics STV2112B Datasheet

BUS-CONTROLLED PAL/SECAM TV PROCESSOR

I2C BUSCONTROL OF ALLFUNCTIONS

INTEGRATEDFILTERS (TRAP, BANDPASS, CLOCHE)

INTEGRATEDLUMINANCE DELAYLINE

PAL/SECAMCHROMADEMODULATORS

AUTOMATIC CUT-OFF CURRENTLOOP

TWORGB INPUTS

SVHSSWITCH

TWOPLLs HORIZONTAL DEFLECTION

VERTICALCOUNT DOWN

VERYFEW EXTERNALCOMPONENTS

DESCRIPTION

The STV2112Bis a fully bus controlledIC for TV luma, chroma and deflectionprocessing.

Used with STV8224(PIF/SIF/switches),TDA1771 orTDA8174(framebooster),STV2180(delayline), itallowsto designa PAL/SECAM(BGDKIL)setwith very few externalcomponentsand no adjustment.

SHRINK42

(PlasticPackage)

ORDER CODE :

STV2112B

PIN CONNECTIONS

CHROMA/SCANNING GROUND

CHROMA LOOP FILTER

ACC CONTROL CAP ACITOR

CLOCHE FILTER TUNING

VOLUME AND MUTE CONTROL VOLTAGE

IF STANDARD AND SWITCH S ELECTION

EXTERNAL BLUE INPUT

EXTERNAL GREEN INPUT

EXTERNAL RGB INSERTION

CVBS OR LUMINANCE INPUT

XTAL2 SELECTION

4.43MHz XTAL

DATAWIRE I

CLOCK WIRE I

OSD GREEN INPUT

OS D RGB INSERTION

EXTERNAL RED INPUT

C BUS

FILTER TUNING

OS D BLUE INPUT

OS D RED INPUT

ACC SDA SCL

VOL

SWI

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

GND2 V

SELECT

CXTL1

CLPF

FTUN1 FTUN2

BOSD GOSD

ROSD

FBOSD

BEXT

GEXT

REXT

FBEXT

Y/CVBS

GND1

42 41 40 39 38 37 36 35 34 33 32 31 30 29 28 27 26 25 24 23

CC2

BYO RYO RYI BYI LFB/SC HOUT VOUT VAMP SLPF SXTL BCL ICAT RO GO BO CR CB CG CHR/SVHS V

CC1

CHROMA/SCANNING/BUS SUPP LY B-Y OUTPUT R-Y OUTPUT R-Y INPUT B-Y INPUT LINE FLYBACK INPUT/SANDCASTLE OUTP UT HORIZONTAL OUTP UT VERTICAL OUTPUT AMPLITUDE CONTROL VOLTAGE SCANNING LOOP FILTER 503kHz CERAMIC BEAM CURRENT LIMITER CATHODE CURRENT MEASUREMENT RED OUTPUT GREEN OUTPUT BLUE OUTPUT RED CUT-OFF CAPACITOR BLUE CUT-OFF CAPACITOR GREEN CUT-OFF CAPACITOR CHROMINANCE INPUT/SVHS S ELECTION VIDEO SUP PLYBUS/VIDEO GROUND

2112B-01.EPS

August 1998

1/24

STV2112B

BLOCKDIAGRAM

ICAT

292827

BCL

VOUT

VAMP34

HOUT

EXTERNAL OSD

15 14 13 12

FB RG BFBRGB

R-Y B-Y

STV2112B

BLANKING

AUTO CUT-OFF

BLACK&WHITE

RGB SWITCHES

Contrast

MATRIX

SATURATION

BRIGHTNESS

CONTROL

CONTRAST

FRAME

SCANNING

VIDEO

IDENTIFICATION

SYNC

SEPARATOR

LINE

CUT-OFF DRIVE STD

CONT SAT BRIG

BUS

SHARP

PAL

DEMODULATORS

SCANNING

DECODER

6 7 11 10

LFB/SC

SXTAL SLPF

SDA SCL

GND2 SWI VOLCLPF R-Y B-Y

2/24

CC2

CC1

22 42 19 18 17 1639 38

TUNING

CLOCHE

FILTER

TUNING

LINE

DELAY

SHARPNESS

CLOCHE

FILTER TUNING

TRAP BANDPASS

Y/CVBS

SVHS SWITCH

CHR

STANDARD

IDENTIFICATION

ACC5

CHR

ACC

PAL

KILLER

SECAM

DELAYLINE INTERFACE

SECAM

DEMODULATORS

PLL

CXTAL1

SELECT

21 1 373332

GND1

44041

2112B-02.EPS

FUNCTIONAL DESCRIPTION 1 - DEFLECTIONCIRCUIT

Note :

[X,Y] : line number referred to the internal line counternumbering

- Fully integratedsynch. separator , with a low pass filter,a blacklevelalignm entof theY/CVBSinput,a slicinglevelat2/3,1/3ofthesync.pulseamplitude.

- Frame sync. pulse locked on 2 f

frequency to

perfect interlace.

- 500kHzVCOwith an externalceramicresonator.

- Two phase locked loops

•

the first PLL locks theVCO on the video signal frequency,

•

the secondPLLcompensatestheline transistor storage time.

- Three time constantsfor the first PLL.

• thelongtimeconstantisusedfornormaloperation

• the short time constant is automatically used

duringthe frameretrace andin searchmodeof VCRwhen the frame pulseis outside[258,264] and [309,314].

• verylongtimeconstantwhennovideorecognition Timeconstantsin normaloperation (automaticselectionof timeconstants):

50Hz input signal:

- short time constant : [306,21]

- long timeconstant : the restof thefield

• inhibition of the firstPLL:

the first locked loop is openedfrom line 309 to line 4.5 (or 314)in 50Hzmode.

• thetimeconstantsvaluesarechosenby means

of externalcomponents.

• possibility to force the short time constant

throughthe bus.

• possibility to force the very long time constant

throughthe bus.

- Video identification : coincidence detector between the line synchro top and a line frequency windowfromthefirstPLL.The videoidentification status isavailablein the output registerof theI

bus decoder.

- 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 thesandcastlegenerator.

- Frame synchrowindow : [248,352] catching

- Field frequencyselection windows: [288,352] 50Hzmode selection window

- frame blankingpulse: from line 0 to 21 in 50Hzmode

- Verticaloutputpulse is 10.5 lines long.

- Horizontal output pulse : 28µs line pulse on an open collectoroutput;

- Start up circuit : the horizontaloutput is at a high

STV2112B

level when V shutting down, horizontal pulses are disabled when V

- Soft-start circuit : the duty cycleof the horizontal outputis78%(Thigh/(Thigh+TLow))whenV is lower than(0.75x V During the falling time, a 78% duty cycle HOUT pulse is provided when V (0.60 x V

CC2

- Possibility to disable the horizontal output pulse through the bus (forcea high levelon HOUT).

- Horizontal position adjustmentcontrolledby bus.

- Bus controlledoutputvoltageto adjustthevertical amplitude;thisvoltagepermitsto adjusttheslope of the verticalsawtoothgeneratedbytheexternal framebooster.

- 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 theverticalpulseis 0.1Vwhen16/9 isselected, 2V when4/3 isselected.

- Combined flyback input and sandcastle output (Pin 37). Two thresholdson LFB/SCOPin : The lowestthreshold(0.7V) permitsto extractthe line blanking pulse ; the highest threshold (2V) permits to extractthe line pulsefor PLL2. Thesandcastle signal at Pin 37 is used to control the externalbasebandchroma delayline.

2 - FILTERS

- Integratedtrap filter:

−3dB

−

Q =

Center frequency :

- 4.43MHzfor PAL

- 4.25MHz,for SECAM (f

rejectionbetween 4.1MHzand 4.4MHz)

- Integratedchroma bandpass: Q = 3.5, Centerfrequency=4.43MHz

- Integratedcloche filterfor SECAM: Q = 16, Centerfrequency = 4.286MHz

- Integrateddelay line : Bandwidth= 8MHz

- Integratedlow pass filter for deflectionpart.

- Allfil t ersaretunedwitharefer e ncephaselockedloop. ThePLLconsistsofa lowpassfilter,aphasecomparator,a loopfilter(withanexternalcapacito r) .Thereferencesign alisthecont i nuouscarr i erwavefromthe VCO (4.43MHz). The PLL adjusts the center frequency of the lowpass so that it is equal to the referencesignal.ThetuningvoltageofthePLLisused toadjustallotherfilters.Theclochefilterisfinetuned withasecondPLLoperatingduringframeretrace.

increases from 0 to 6.8V. On

isbelow 6.2V.

),duringtherisingtime.

CC2

CC1

Q = 1.7 at sharp.min

−

3dB

Q =3.0 atsharp. max

= 3MHz; -20dB

-3dB

CC1

is lower than

3/24

STV2112B

FUNCTIONAL DESCRIPTION(continued) 3 - VIDEO CIRCUIT

- 2 RGB inputs : RGB (OSD) input has priority against the RGBext. Maximum contraston RGB (OSD).-12dB range contrast controlonRGBext. Possibility to disable the RGBext insertion throughthe bus.

- Oversizeblanking capabilityon FB(OSD)(Pin15) input. TheRGB ouputswill be blankedwhenthe voltage on Pin 15 willexceed the secondthreshold at1.9V (blanking threshold) : the wholefield is blankedbutnottheinsertedcut-offpulses.The OSD insertionthresholdis0.7V.

- Automaticcut-off current loop : 2V cut-off range. Sequential cut-off current measurement during the three lines after the frame blanking signal. Leakage currentmeasurement during the frame blanking,memorizationon an internalcapacitor.

- Warm up detector.

- Beam current limiterDC voltageinput. The beam current limiter control voltage will act on contrast first, then the brightness will be decreasedwhencontrastattenuationreaches-5dB.

- Bus control of the red, green and blue channel gain (Whitepoint adjustment)

- Bus controlof the red andgreenDC levels(black point adjustment)

- PALand SECAM matrix).

- Switch-off of the trapfilterin SVHS mode.

- Buscontrolledcontrastonluminance(20dBrange)

- Bus controlledsaturation (50dBrange)

- Bus controlled brightness : 40% range at maximum contrast.

- Bus controlled sharpness (peaking) ; sharpness active in PALstandardonly.

- Noise coring function on sharpness.

4 - CHROMA CIRCUIT

4.1 - PAL/SECAMDecoders

- SVHSinputs ; bus controlledSVHS mode.

- 30dB range ACC

- Use of an external ba se b and de lay line (STV2180 recommended)

- Automaticstandard identification,with possibility to forcethe standardthroughthe bus.

4.2 - PALDecoder

- ACC done by peak detector on synchronousdemodulationof the burst

- Fully integratedkillerfunctions.

- VCO using crystal4.43MHz XTALSPECIFICATION: Frequency:

4.433619MHz(PAL/SECAM)

Vibrationmode :Fondamental,seriesresonance (no serial capacitor) Motional capacity : 13fF ±3fF Resonance resistance: < 70Ω Shunt capacitance: < 7pF Spuriousresponse: Noresonance at 3*f

and±90odemodulationangles forPAL

-0

±3kHz

4.3 - SECAMDecoder

- ACC

- Fully integratedkiller

- Two integrateddiscriminatorswith two PLL

- Integrateddeemphasis

4.4 - StandardIdentification

- Sequentialidentification.

- 2 identificationsequences: PALmode, SECAMmode

- PALpriority

- the SECAM mode is locked after two identified SECAMsequences

- the SECAM mode can be selectedin 50Hzonly

- Blanking of the (R-Y) and B-Y) outputs during color searchmode.

5 - OTHER FUNCTIONS :

IF CONTROLS

5.1 - VolumeControl and Mute

Thevolumecontrolvoltagerangeon Pin10is from

0.5V to5V.

Alow voltageon Pin 10 (below 0.2V)will mute the FM demodulatorof the IF circuit STV8224.

It will put thevolumeat theminimumleveland thus there willbeno soundeitherinTVmodeor SCART mode.

The volume control voltageand the mute levelare controlledby the bus.

5.2- IF Standardand TV/SCARTMode Selection

The selection of IF standard (positive or negative visionmodulation)andtheTV/SCARTmode iscontrolledbythe bus.Theselectionis convertedinfour voltageson Pin 21.

The lowest voltage selects the TV mode and the NEGATIVEvision modulation.

The highest voltage (open collector output with internalpull-upresistorto V

) selects the SCART

mode and the NEGATIVE vision modulation. The two other intermediate voltages select either

TV mode and POSITIVE vision modulation or SCARTmode and POSITIVEvision modulation.

4/24

STV2112B

I2C BUS SPECIFICATION GeneralComments

SlaveAddress: 8A(HEX)(1000101X) WRITEMODEDATAFORMAT

Slave Address Register Address Data

1000 1010

(8A)

Thenot usedbits in data byte mustbe put to ”0”.

READ MODEDATAFORMAT

Slave Address Data

1000 1011

(8B)

MSB on the left, LSB on the Right.

MSB LSB

XXXXXXXX

X: not significantbit - S : significantbit

XXXS SSSS

(from 00 to 11HEX)

XXSS SSSS

(6 significant bits Max.)

SSSS SSSS

(8 significant bits)

InputSignals

(Write Mode)

VIDEO

Address

Dec (HEX)

0 (00) Contrast 5 XXX0 0000 = -20dB

0 (00) External Fast Blanking Enable 1 XXSX XXXX

1 (01) Saturation 6 XX00 0000 = -44dB

2 (02) Brightness 5 XXX0 0000 = -20%

2 (02) RGB Outputs Blanking 1 XXSX XXXX

3 (03) Red Drive Adjust (white point red adjust) 6 XX00 0000 = -6dB

4 (04) Red Cut-off Adjust 6 XX00 0000 = +150mV

5 (05) Green Drive Adjust (white point green adjust) 6 XX00 0000= -6dB

6 (06) Green Cut-off Adjust 6 XX00 0000 = +150mV

7 (07) Blue DriveAdjust (white point blueadjust) 6 XX00 0000 = -6dB

8 (08) Sharpness 3 XXXX X000 = Peaking Min.

Description

Data

(Bits)

Comments

XXX1 1111 = 0dB

0 = RGBext insertionenable 1 = RGBext insertiondisable

XX11 1111 = +6dB

XXX1 1111 = +20%

0 = Normal mode 1 = Blanking active

XX11 1111 = 0dB

XX11 1111 = -150mV

XX11 1111 = 0dB

XX11 1111 = -150mV

XX11 1111 = 0dB

XXXX X111 = PeakingMax.

5/24

STV2112B

I2C BUS SPECIFICATION(continued) InputSignals (Write Mode) (continued)

CHROMA

Address

Dec (HEX)

9 (09) Not used

10 (0A) Standard Selection 4 XXXX SSSS

10 (0A) SVHS Selection 1 XXXS XXXX

Description

Data

(Bits)

0000 = PAL/XTAL1 (4.43MHz) 0100 = SECAM/XTAL1 011X = Auto/90

0001 = Not allowed 0010 = Not allowed 0011 = Not allowed 0101 = Not allowed 1000 = Not allowed 1001 = Not allowed 1010 = Not allowed 1011 = Not allowed 111X = Not allowed 1100 = Not allowed 1101 = Not allowed

0 = No SVHS (CVBS mode) 1 = SVHS mode

Comments

DEFLECTION

Address

Dec (HEX)

11 (0B) Horizontal Shift 6 XX00 0000 = -2.5µs

12 (0C) Vertical Amplitude 6 XX00 0000 = 1.2V

13 (0D) Vertical Position 3 XXXX X000 = 3.8V

13 (0D) 50/60Hz Selection 2 XXXS SXXX

13 (0D) Horizontal Output (HOUT) Safety 1 XXSX XXXX

14 (0E) PLL1 Time Constant 2 XXXX XXSS

14 (0E) Interlace 1 XXXX XSXX

14 (0E) 4/3 16/9 Selection 1 XXXX SXXX

Description

Data

(Bits)

XX11 1111 = +2.5µs

XX11 1111 = 6.2V

XXXX X111 = 6.3V

00 = Automode 01 = Not allowed 10 = 50Hz 11 = Not allowed

0 = Normal mode 1 = HOUT disabled (high level)

00 = Normal mode (Auto) 01 = Short time constant 10 = Very long time constant 11 = PLL1 inhibition(open loop)

0 = Interlace 1 = DE-Interlace

0 = 4/3 (V 1 = 16/9 (V

OUT-Low

Comments

= 2V)

= 0.1V)

6/24

I2C BUS SPECIFICATION(continued) InputSignals (Write Mode) (continued)

OTHERS

Address

Dec (HEX)

15 (0F) Volume 6 XX00 0000 = 0.5V

16 (10) Mute 1 XXXX XXXS

16 (10) IF Standard / AV Switch 2 XXXX XSSX

16 (10) Not Used 1 XXXX SXXX

16 (10) Cut-off Pulse Position 1 XXXS XXXX

17 (11) Only for Test 6 XXSS SSSS

Description

Data

(Bits)

XX11 1111 = 5V

0 = Mute not active 1 = Mute active

00 = INT/FM (negative) 01 = INT/AM (positive) 10 = EXT/AM (positive) 11 = EXT/FM (negative)

S = 0 default value

0 = lines 23/24/25in50Hz, 1 = Not allowed

00 0000 = Test mode notactive

STV2112B

Comments

OutputSignals

(ReadMode)

READ REGISTER

Description Data (Bits) Comments

Field Frequency 1 XXXX XXXS

Video Identification 1 XXXX XXSX

SVHS Status 1 XXXX XSXX

Standard Status 3 XXSS SXXX

Circuit Identification 2 SSXX XXXX

1 = 50Hz 0 = not 50Hz

1 = No Identification 0 = Video Identification

1 = No SVHS 0 = SVHS

111 = PAL/XTAL1 (4.43MHz) 110 = not to be used 101 = SECAM/XTAL1 011 = not to be used 010 = not to be used X00 = Color off

11 = STV2118A/2116/2112 10 = STV2116A

01 = STV2112B

00 = STV2216

7/24

STV2112B

I2C BUS SPECIFICATION(continued) Bus Register Initial Conditions

Notused bitsare presetto ”0”.

Address

Dec (HEX)

0 (00) XX01 0000 Mid. contrast ; RGBext insertionenable 1 (01) XX10 0000 Mid. saturation 2 (02) XX01 0000 Mid. brightness ; Blanking :normal mode 3 (03) XX10 0000 Mid. RED driveadjust 4 (04) XX10 0000 Mid. RED cut-off adjust 5 (05) XX10 0000 Mid. GREEN drive adjust 6 (06) XX10 0000 Mid. GREEN cut-offadjust 7 (07) XX10 0000 Mid. BLUE drive adjust 8 (08) XX00 0100 Mid. sharpness

9 (09) XX10 0000 Not used 10 (0A) XX00 0110 Auto search color standard ; no SVHS 11 (0B) XX10 0000 Mid. horizontal shift 12 (0C) XX10 0000 Mid. vertical amplitude 13 (0D) XX00 0100 Mid. vertical position ; Auto search field frequency ; HOUT : normal mode 14 (0E) XX00 0000 PLL1 time constant : normal mode ; Interlace; 4/3 selection 15 (0F) XX10 0000 Mid. volume 16 (10) XX00 0000 Mute not active ; INT/FM IF mode; Not used ;

17 (11) XX00 0000 Test mode not active

Data Initial

Value

Comments

Cut-off pulses on lines23/24/25 in 50Hz

8/24

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