SGS Thomson Microelectronics STV0056AF Datasheet

SATELLITESOUNDAND VIDEO PROCESSOR

SOUND

.

TWO INDEPENDENT SOUND DEMODULATORS

.

PLL DEMODULATION WITH 5-10MHz FRE­QUENCYSYNTHESIS

.

PROGRAMMABLE FM DEMODULATOR
BANDWIDTH ACCOMODATING FM DEVIA­TIONSFROM ±30kHz TILL ±400kHz

.

PROGRAMMABLE 50/75µs, J17 OR NO DE­EMPHASIS

.

WEGENERPANDASYSTEM

.

TWO AUXILIARYAUDIOINPUTS AND OUTPUTS

.

GAIN CONTROLLED AND MUTEABLE
AUDIOOUTPUTS

.

HIGH IMPEDANCE MODE AUDIO OUTPUTS
FORTWINTUNERAPPLICATIONS

VIDEO

.

COMPOSITE VIDEO 6-bit 0 to 12.7dB GAIN
CONTROL

.

COMPOSITEVIDEOSELECTABLEINVERTER

.

TWO SELECTABLE VIDEO DE-EMPHASIS
NETWORKS

.

6 x 3 VIDEOMATRIX

.

BLACK LEVEL ADJUSTABLE OUTPUT FOR
ON-BOARDVIDEOCRYPTDECODER

.

HIGH IMPEDANCE MODE VIDEO OUTPUTS
FORTWINTUNERAPPLICATIONS

MISCELLANEOUS

.

22kHzTONEGENERA TI ONFORLNBCONTROL

.

I2C BUSCONTROL
CHIPADDRESSES= 06

.

LOW POWER STAND-BY MODE WITH AC­TIVEAUDIOANDVIDEO MATRIXES

HEX

OR46

HEX

STV0056AF

TQFP64 (10 x 10mm)

(Thin Plastic Quad Flat Pack)

ORDER CODE : STV0056AF

DESCRIPTION

TheSTV0056AFBICMOSintegratedcircuit realizes
allthenecessarysignalprocessingfromthetunerto
theAudio/Videoinputandoutputconnectorsregard­lessthe satellitesystem.

February 1998

1/27

STV0056AF

PIN CONNECTIONS

GND

S2 VID OUT

VOL L

S2 VID RTN

S2 OUTL

CLAMP IN

S2 OUTR

UNCL DEEM

VIDEEM2/22kHz

V 12V

V 12V

VIDEEM1

VGND

VGND

NC

B-BAND IN

S2 RTN L

S2 RTNR

FM IN

S3 RTN L

S3 RTNR

AGC L

S3 OUT L

S3 OUTR

SCL

SDA

HA

J17 R

J17 L

XTL

V

DD

1213141516

17
18
19
20
21
22
23
24
25

IO

26
27
28
29
30
31
32

5V

38 39 40 41 42 43 44 45 46 47 4833 34 35 36 37

NC

GND 5V

U75 L

DET L

CPUMP L

NC

AGC R

AMPLKL

REF

V

A 12V

AGND L

AGND L

A 12V

1234567891011

DET R

AMPLK R

PIN ASSIGNMENT

Pin Number Name Function

1 GND Connected to the Lead Frame
2 S2 VID OUT VCR-Scart 2 VideoOutput
3 VOL L Volume Controlled Audio Out Left
4 S2 VID RTN VCR-Scart 2 Video Return
5 S2 OUT L Fixed Level Audio OutputLeft (to VCR)
6 CLAMP IN Sync-Tip Clamp Input
7 S2 OUT R Fixed Level Audio OutputRight (to VCR)
8 UNCL DEEM Unclamped Deemphasized Video Output
9 VIDEEM2/22kHz Video Deemphasis 2 or 22kHz Output

10 - 11 V 12V Video 12V Supply

12 VIDEEM1 Video Deemphasis 1

13 - 14 V GND Video Ground

15 NC
16 B-BAND IN Base Band Input
17 S2 RTN L Auxiliary Audio Return Left (from VCR)
18 S2 RTN R Auxiliary Audio Return Right (from VCR)
19 FM IN FM Demodulator Input
20 S3 RTN L Auxiliary Audio Return Left (from decoder)

64

S1 VIDOUT

63

S3 VIDOUT

62

VOL R

61

S3 VIDRTN

60

S1 VIDRTN

59

LEVELR

58

PKIN R

57

FCR

56

AGNDR

55

FCL

54

PKIN L

53

LEVELL

52

PKOUTL

51

PKOUTR

50

I

49

U75 R

REF

CPUMPR

0056F-01.EPS

0056F-01.TBL

2/27

PIN ASSIGNMENT(continued)

Pin Number Name Function

21 S3 RTN R Auxiliary Audio Return Right (from decoder)
22 AGC L AGC Peak Detector Capacitor Left
23 S3 OUT L Auxiliary Audio Output L (to decoder)
24 S3 OUT R Auxiliary Audio Output R (to decoder)
25 I/O/22kHz Digital Input/Output or 22kHz Output
26 SCL I
27 SDA I
28 HA Hardware Address
29 J17 R J17 Deemphasis Time Constant Right
30 J17 L J17 Deemphasis Time Constant Left
31 XTL 4/8MHz Quartz Crystal or Clock Input
32 V

5V Digital 5V Power Supply

DD

34 NC Not Connected
33 GND 5V Digital Power Ground
35 CPUMP L FM PLL Charge Pump Capacitor Left
36 DET L FM PLL Filter Left
37 U75 L Deemphasis Time Constant Left
38 AMPLK L Amplitude Detector Capacitor Left
39 AGC R AGC Peak Detector Capacitor Right
40 NC

41 - 42 A GND L Audio Ground

43 V

REF

44 - 45 A 12V Audio 12V Supply

46 AMPLK R Amplitude Detector Capacitor Left
47 DET R FM PLL Filter Right
48 U75 R Deemphasis Time Constant Right
49 CPUMP R FM PLL Charge Pump Capacitor Right
50 I

REF

51 PK OUT R Noise Reduction Peak Detector Output Right
52 PK OUT L Noise Reduction Peak Detector Output Left
53 LEVEL L Noise Reduction Level Left
54 PK IN L Noise Reduction Peak Detector Input
55 FC L Audio Roll-off Left
56 A GND R Audio Ground
57 FC R Audio Roll-off Right
58 PK IN R Noise Reduction Peak Detector Input Right
59 LEVEL R Noise Reduction Level Right
60 S1 VID RTN TV-Scart 1 Video Return
61 S3 VID RTN Decoder-Scart Video Return
62 VOL R Volume Controlled Audio Out Right
63 S3 VID OUT Decoder-Scart Video Output
64 S1 VID OUT TV-Scart 1 VideoOutput

2

C Bus Clock

2

C Bus Data

2.4V Reference

Current Reference Resistor

STV0056AF

0056F-01.TBL

3/27

STV0056AF

PIN DESCRIPTION
1 - Sound Detection

FMIN

This is the input to the two FM demodulators. It
feeds two AGC amplifiers with a bandwidth of at
least 5-10MHz. There is one amplifier for each
channelboth withthe sameinput. TheAGC ampli­fiers have a 0dB to +40dBrange.

=5kΩ, Mininput = 2mVPPper subcarrier.

Z

IN

Max input = 500mV
addedtogether,when their phases coincide).

AGC L, AGC R

AGC amplifiers peak detector capacitor connec­tions.The output current hasan attack/decayratio
of 1:32. That is the ramp up current is approxi­mately 5µA and decay current is approximately
160µA. 11V gives maximum gain. These pins are
also driven by a circuit monitoring the voltage on
AMPLKL and AMPLK R respectively.

AMPLKL, AMPLK R

The outputs of amplitude detectors LEFT and
RIGHT.Eachrequiresa capacitorand a resistorto
GND. The voltage across this is used to decide
whetherthereis a signalbeing receivedby the FM
detector.The level detector output drives a bit in
the detectorI

2

C bus controlblock.
AMPLK L and AMPLK R drive also respectively
AGCLand AGCR. For instancewhen the voltage
on AMPLK L is > (V

frompin AGCLto reduce the AGCgain.

V

REF

DET L, DETR

Respectivelythe outputsofthe FMphasedetector
leftand right.
This is for the connectionof an external loop filter
for the PLL. The output is a push-pull current
source.

CPUMPL, CPUMPR

The output from the frequency synthesizer is a
push-pullcurrentsourcewhichrequiresa capacitor

(max when all inputs are

PP

+1VBE) it sinks current to

REF

to groundto derivea voltageto pull the VCOto the
target frequency.The outputis ±100µA to achieve
lockand±2µAduringlocktoprovidea trackingtime
constant of approximately10Hz.

V

REF

This isthe audio processorvoltage referenceused
through out the FM/audio section of the chip. As
such it is essential that it is well decoupled to
ground to reduce as far as possible the risk of
crosstalk and noise injection. This voltage is de­rived directlyfrom the bandgapreferenceof 2.4V.
The V

output can sink up to 500µA in normal

REF

operationand 100µAwhen in stand-by.

I

REF

Thisis abufferedV

outputtoan off-chipresistor

REF

to produce an accurate current reference, within
the chip, for the biasing of amplifiers with current
outputs into filters.It is also required for the Noise
reduction circuit to provide accurate roll-off fre­quencies. This pin should not be decoupled as it
would inject current noise. The target current is
50µA±2% thusa 47.5kΩ ±1% is required.

A 12V

Double bonded main power pin for the audio/FM
section of the chip. The two bond connectionsare
to the ESD and to power the circuit and on chip
regulators/references.

A GND L

This groundpin is double bonded :

1) to channelLEFT : RF section & VCO,

2) to both AGC amplifiers, channel LEFT and
RIGHTaudio filtersection.

A GND R

This groundpin is double bonded :

1) to the volume control, noise reduction system,
ESD + Mux + V

REF

2) to channelright : RF section& VCO

4/27

PIN DESCRIPTION(continued)
2 - Baseband Audio Processing

PK OUT L, PK OUT R, PK OUT

The noise reduction control loop peak detector
outputrequiresa capacitortogroundfrom thispin,
and a resistor to V

pin to give some accurate

REF

decaytimeconstant.Anonchip5kΩ ±25%resistor
and external capacitor give the attack time.

PK IN L, PK IN R or PK IN

Eachof thesepinsis an inputtoa controllooppeak
detector and is connected to the output of the
offchipcontrolloop band pass filter.

STV0056AF

U75 L, U75 R

External deemphasis networks for channels left
andright.Foreachchannelacapacitorandresistor
in parallel of 75µs time constant are connected
betweenhereandV
sis. Internallyselectableis an internalresistor that
canbeprogrammedto beaddedin parallelthereby
convertingthe network to approx 50µs de-empha­sis (see controlblock map). The value of theinter­nal resistors is 54kΩ ±30 %. The amplifier for this
filter is voltage input, current output ; with ±500mV
input the output will be ±55µA.

toprovide75µsde-empha-

REF

LEVELL, LEVELR

Respectivelythe audio left and right signals of the
FMdemodulators are output to level L and level R
pins through an input follower buffer. The off-chip
filters driven by these pins must include AC cou­plingto thenext stage (PK IN L and PK IN R pins
respectively).

FC L, FC R

The variable bandwidth transconductance ampli­fier has a currentoutput which is variabledepend­ingon the input signalamplitude as defined by the
control loop of the noise reduction. The output
current is then dumped into an off-chip capacitor
whichtogetherwith the accuratecurrent reference
definethemin/maxrolloff frequencies.Aresistorin
serieswith acapacitoris connectedtoground from
thesetwo pins.

J17 L, J17 R

The external J17 de-emphasisnetworks for chan­nels left and right. The amplifier for this filter is
voltageinput, current output. Output with ±500mV
input will be ±55µA.
ToperformJ17 de-emphasiswiththeSTV0042,an
externalcircuit isrequired.

VOLL, VOL R

The main audio output from the volume control
amplifierthe signalto get output signalsas highas
2V

(+12dB) on a DC bias of 4.8V. Control is

RMS

from +12dB to -26.75dB plus Mute with 1.25dB
steps.Thisamplifierhasshortcircuitprotectionand
is intendedto drivea SCARTconnectordirectlyvia
AC couplingand meetsthe standardSCART drive
requirements. These outputs feature high imped­ance mode forparallel connection.

S2 OUT L, S2 OUT R, S3 OUT L, S3 OUT R

These audio outputs are sourced directly from the
audio MUX, and as a result do not include any
volume control function. They will output a 1V

RMS

signal biased at 4.8V.They are short circuit pro­tected. These outputs feature high impedance
mode for parallel connection and meet SCART
drive requirement.

S2 RTN L, S2 RTN R, S3 RTN L, S3 RTN R

These pins allow auxiliaryaudio signalsto be con­nected to the audio processor and hence makes
use of the on-chip volume control. For additional
detailsplease refer to the audio switchingtable.

5/27

STV0056AF

PIN DESCRIPTION(continued)
3 - Video Processing

B-BAND IN

AC-coupledvideo input from a tuner.
Z

> 10kΩ ±25%. This drives an on-chip video

IN

amplifier. The other input of this amp is AC
groundedby being connectedto an internalV
The video amplifier has selectable gain from 0dB
to 12.7dB in 63 steps and its output signal can be
selectednormalor inverted.

UNCLDEEM

Deemphasizedstill unclamped output.It isalso an
input of the video matrix.

VIDEEM1

Connected to an external de-emphasis network
(forinstance 625 lines PALde-emphasis).

VIDEEM2/ 22kHz

Connected to an external de-emphasis network
(forinstance525linesNTSCorothervideo de-em­phasis).Alternativelyaprecise22kHz tonemaybe
output by I

2

C bus control.

CLAMPIN

This pin clamps the most negative extreme of the
input(the sync tips)to 2.7V

(or appropriatevolt-

DC

age). The video at the clamp input is only 1V
This clamped video which is de-emphasised, fil­tered and clamped (energy dispersal removed) is
normal, negative syncs, video. This signal drives
the Video Matrixinput called Normal Video.
It hasa weak(1.0µA ±15 %) stablecurrentsource
pullingthe inputtowardsGND. Otherwisethe input
impedanceis very high at DC to 1kHz Z
Video bandwidth through this is -1dB at 5.5MHz.
TheCLAMP input DC restore voltageis then used
as a means for getting the correct DC voltage on
the SCART outputs.

S3 VID RTN

This input can be driven for instance by the de­coder.This input hasa DC restorationclampon its
input.Theclampsink current is 1µA ±15%with the
bufferZ

>1MΩ.

IN

S2 VID RTN, S1 VID RTN

Externalvideoinput1.0VppACcoupled75Ωsource
impedance.This input has a DC restorationclamp
on its input. The clamp sink current is 1µA ±15%
withthe bufferZ

>1MΩ.This signalis an input to

IN

the Video Matrix.

>2MΩ.

IN

REF

PP

onthe O/P. Thesignalis video2.0V

PP

with sync tip = 1.2V.These pins get signals from
the Video Matrix. The signal selected from the
Video Matrix for output on this pin is controlled by
a control register. This output also feature a high
impedancemode for parallel connection.

.

S3 VID OUT

This output can drive for instance a decoder. Also
it is able to pass 10MHz ; Z
this pin will be 2V

. The black level of the ouput

PP

<75Ω. Video on

OUT

video signal can be adjusted through I
trol to easily interface with on-board Videocrypt
decoder. This output feature an high impedance
mode for parallel connection.

V 12V

+12Vdoublebonded: ESD+guardringsandvideo
circuitpower.

V GND

Doubledbonded.Clean VID INGND. Strategically
placed video power ground connection to reduce
video currents getting into the rest of the circuit.

4 - ControlBlock

GND 5V

.

The main power ground connectionfor the control
logic, registers, the I

2

C bus interface, synthesizer

& watchdogand XTLOSC.

VDD5V

Digital +5V power supply.

SCL

Thisis theI2C busclockline.Clock=DCto100kHz.
Requiresexternal pull up eg. 10kΩ to 5V.

SDA

This isthe I2Cbus data line.Requiresexternalpull
up eg. 10kΩ to 5V.

I/O / 22kHz

Generalpurposeinput outputpin or 22kHz output.

XTL

Thispinallowsfor theon-chiposcillatorto beeither
used with a crystal to ground of 4MHzor 8MHz,or
to be driven by an external clock source. The
external source can be either 4MHz or 8MHz. A
programmablebitinthecontrol blockremovesa ÷2
block when the 4MHz option is selected.

5.5MHzBW

2

C bus con-

S1 VID OUT,S2 VID OUT

Video drivers for SCART 1 and SCART 2. An
externalemitter follower buffer is requiredto drive
a 150Ω load. The average DC voltage to be 1.5V

6/27

HA

Hardwareaddresswith internal 135µApull down.
Chip address is 06 when this pin is grouded and
chip address is 46 when connectedto V

DD

.

GENERAL BLOCKDIAGRAM

STV0056AF

From Tuner

Video

Processing

FromTV,

VCR/Decoder

FM

B-BAND

From Tuner

Demodulation

2 Channels

Wegener

Panda+

Deemphasis

22kHz to LNB

STV0056AF

VIDEOPROCESSINGBLOCK DIAGRAM

LPF

I/O/22kHz

B-BAND IN

25

22kHz
TONE

16

± 1

G

2

2

6x3

Video

4

Matrix

Audio
Matrix

+

Volume

2

I

C Bus

Interface

NTSC

PAL

VIDEEM1VIDEEM2/22kHz

9128

Baseband

3

3

To TV, VCR/Decoder

Active in Stand-by

UNCLDEEM

Deemphasized

÷ 2

0056F-02.EPS

CLAMPIN

S3 VID RTN

S2 VID RTN

S1 VID RTN

6

CLAMP

CLAMP

61

CLAMP

4

CLAMP

60

STV0056AF

Normal

DecoderReturn

VCRReturn

TV Return

BLACKLEVEL

ADJUST

63

64 2

To Decoder To VCR

S1 VID OUT

S2 VID OUTS3 VID OUT

To TV

0056F-03.EPS

7/27

STV0056AF

AUDIO PROCESSINGBLOCK DIAGRAM (CHANNELRIGHT)

AUDIO R

47

a

ANRS

K3

b

4

abc

K4

b

a

K6

-6dB -6dB

24 21 51 58 59 57 7 18 62

AUDIO

DEEMPHASIS

29 48

STV0056AF

K2

a
ba

c

abc

6dB6dB

K1

b
c

K5

MONO

STEREO

DET R

PLL

FILTER

Audio

Decoder Out

FC R

PK IN R

S3 OUT R

S3 RTN R

Audio
Decoder Return

LEVEL R

PK OUT R

J17 R

U75 R

DECODER VCR

AUDIO PROCESSINGBLOCK DIAGRAM(CHANNELLEFT)

AUDIOL

36

a

ANRS

K3

K4

abc

K6

23 20 52 54 53 55 5 17 3

b

a

-6dB -6dB

b

4

AUDIO

DEEMPHASIS

30 37

S2 OUT R

S2 RTN R

STV0056AF

K2

a
ba

c

abc

6dB6dB

K1

b
c

K5

MONO

STEREO

VOL R

TV

0056F-04.EPS

8/27

DET L

PLL

FILTER

Decoder Out

FC L

PK IN L

S3 OUT L

Audio

S3 RTN L

Audio
DecoderReturn

DECODER VCR

LEVEL L

PK OUT L

J17 L

U75 L

S2 OUT L

S2 RTN L

VOL L

TV

0056F-05.EPS

AUDIO SWITCHING

STV0056AF

AUDIO

DEEMPHASIS

+ ANRS

AUDIOPLL

DECRTN

AUXIN K

K

1a

K

1b

1c 6b

VOL OUT AUXOUT

K

K

K

5b

5c

5a

FM DEMODULATION BLOCK DIAGRAM

FM IN

19

AGC

LEVEL

DETECTOR1

AGC R

39

LEVEL

DETECTOR2

K

K

K

DECOUT

Bias

6c

6a

SW1

0056F-06.EPS

Phase
Detect

:a→ANRS input non-scrambledaudio

K

4

b → ANRS input descrambledaudio

K

a
b
b

c

a
b
b

c

K

2

1
2

1
2

3

a

No ANRS, No De-emphasis

a

No ANRS, 50µs

a

No ANRS, 75µs

a

No ANRS, J17

b

ANRS, No De-emphasis

b

ANRS, 50µs

b

ANRS, 75µs

b

ANRS, J17

AUDIOR

FM dev.

Select.

V

REF

47

49

DET R

CPUMPR

AMPLKR

AGC L

AMPLK L

46

V

REF

AGC

22

38

V

REF

STV0056AF

Reg8 b4

LEVEL

DETECTOR1

LEVEL

DETECTOR2

Reg8 b0

Amp.Detect

WATCHDOG

SW3

Bias

Amp.Detect

WATCHDOG

Phase
Detect

90

VCO

0

SYNTHESIZER

AUDIOL

FM dev.

Select.

V

REF

90

VCO

0

SW2

SW4

36

35

DET L

CPUMP L

0056F-07.EPS

9/27