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TDA4472
Video-IF and Quasi Parallel Sound Processing
Description
The TDA4472 is an integrated bipolar circuit for video/ sound IF (VIF/SIF) signal processing in TV/VCR and multimedia applications. The circuit processes all TV video IF signals with negative modulation (e.g., B/G standard), and the FM/NICAM sound IF signals.
Features
D 5 V supply voltage; low power consumption D Active carrier generation by FPLL principle (frequency-phase-locked-loop) for true synchronous demodulation D Very linear video demodulation, good pulse response and excellent intermodulation figures D VCO circuit operates at picture carrier frequency D Alignment-free AFC without external reference circuit, polarity of the AFC curve is switchable D VIF-AGC with peak sync. detection D Tuner AGC with adjustable take over point Package: SDIP28, SO28 D Alignment-free quasi parallel sound (QPS) mixer for FM/NICAM sound IF signals D Intercarrier output signal is gain controlled (necessary for digital sound processing) D Separate SIF-AGC with average detection D Two independent SIF inputs D Package and relevant pinning is compatible with the multistandard version TDA4470, which simplifies the design of an universal IF module
Ordering Information
Extended Type Number TDA4472-MSD TDA4472-MFLG3 Package SDIP28 SO28 Remarks Delivery in taped form
Rev. A3, 23FEb01
1 (14)
Preliminary Information
TDA4472
Block Diagram
Offset comp. (optional) Loop filter VCO
FPL L
0° 90°
AFC
6 VIF
VIF amp
Video det.
7
CAGC
8
AGC (VIF)
11
10
Tuner AGC FM det.
Supply
Take over point
27 28
SIF 2
SIF amp
Input switch
3
1
SIF 1
2
AGC (SIF)
5
CAGC
94 8719
Figure 1. Block diagram
2 (14)
Preliminary Information
ÏÏ ÏÏ Ï ÏÏ
ÏÏ
ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ
Tuner
ÏÏ ÏÏ
VCO + phase shift
ÏÏ ÏÏ ÏÏ
Ï Ï
Ï Ï
Ï Ï
ÏÏ ÏÏ
ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ ÏÏ Ï Ï
26
18
20
21
Ï Ï
AFC switch
19
22
AFC
12
Video
4,9,16
23 VS 17
CRef
24
Intercarrier (FM / NICAM)
Rev. A3, 23FEb01
TDA4472
Circuit Description
Vision IF Amplifier
The video IF signal (VIF) is fed through a SAW filter to the differential input (Pin 6-7) of the VIF amplifier. This amplifier consists of three AC-coupled amplifier stages. Each differential amplifier is gain controlled by the automatic gain control (VIF-AGC). The output signal of the VIF amplifier is applied to the FPLL carrier generation and the video demodulator. designed for low distortion and large bandwidth. The demodulator output signal passes an integrated low pass filter for attenuation of the residual vision carrier and is fed to the video amplifier. The video amplifier is realized by an operational amplifier with internal feedback and 8 MHz bandwidth (3 dB). An additional noise clipping is provided. The video signal is fed to VIF-AGC and to the video output buffer. This amplifier with a 6 dB gain offers easy adaption of the sound trap. For nominal video IF modulation the video output signal at Pin 12 is 2 Vpp.
Tuner-and VIF-AGC
At Pin 8, the VIF-AGC charges/discharges the AGC capacitor to generate a control voltage for setting the gain of the VIF amplifier and tuner in order to keep the video output signal at a constant level. Therefore, in the case of all negative modulated signals (e.g., B/G standard) the sync. level of the demodulated video signal is the criterion for a fast charge/discharge of the AGC capacitor. The control voltage (AGC voltage at Pin 8) is transferred to an internal control signal, and is fed to the tuner AGC to generate the tuner AGC current at Pin 11 (open collector output). The take over point of the tuner AGC can be adjusted at Pin 10 by a potentiometer or an external dc voltage (from interface circuit or microprocessor).
Sound IF Amplifier and SIF-AGC
The SIF amplifier is nearly identical with the 3-stage VIF amplifier. Only the first amplifier stage exists twice and is switchable by a control voltage at Pin 3. Therefore with a minimal external expense it is possible to switch between two different SAW filters. Both SIF inputs features excellent cross-talk attenuation and an input impedance which is independent from the switching condition. The SIF-AGC is related to the average level of FM-carrier and controls the SIF amplifier to provide a constant SIF signal to the QPS mixer.
FPLL, VCO and AFC
The FPLL circuit (frequency phase locked loop) consists of a frequency and phase detector to generate the control voltage for the VCO tuning. In the locked mode, the VCO is controlled by the phase detector and in unlocked mode, the frequency detector is superimposed. The VCO operates with an external resonance circuit (L and C parallel) and is controlled by internal varicaps. The VCO control voltage is also converted to a current and represents the AFC output signal at Pin 22. A practicable VCO alignment of the external coil is the adjustment to zero AFC output current at Pin 22. At center frequency the AFC output current is equal to zero. The optional potentiometer at Pin 26 allows an offset compensation of the VCO phase for improved sound quality (fine adjustment). Without a potentiometer (open circuit at Pin 26), this offset compensation is not active. The oscillator signal passes a phase shifter and supplies the in-phase signal (0°) and the quadrature signal (90°)of the generated picture carrier.
Quasi-Parallel-Sound (QPS) Mixer
The QPS mixer is realized by a multiplier. The SIF signal (FM or NICAM carrier) is converted to the intercarrier frequency by the regenerated picture carrier (quadrature signal) which is provided from the VCO. The intercarrier signal is fed via an output amplifier to Pin 24.
AFC Switch
The AFC output signal at Pin 22 can be controlled by a switching voltage at Pin 19. It is possible to switch off the AFC.
VCR Mode
For the VCR mode in a TV set (external video source selected), it is recommendable to switch off the IF circuit. With an external switching voltage at Pin 6 or 7, the IF amplifiers are switched off and all signal output levels at Pins 12 and 24 are according to the internal dc voltage.
Internal Voltage Stabilizer
The internal bandgap reference ensures constant performance independent of supply voltage and temperature.
Video Demodulation and Amplifier
The video IF signal, which is applied from the gain controlled IF amplifier, is multiplied with the inphase component of the VCO signal. The video demodulator is
Rev. A3, 23FEb01
3 (14)
Preliminary Information
TDA4472
Pin Description
Vi,SIF1 Vi,SIF1 VSW GND CAGC Vi,VIF Vi,VIF CAGC GND Rtop Itun Vo,vid NC NC 1 2 3 4 5 6 7 8 9 10 11 12 13 14
94 8835
28 27 26 25 24 23 22 21 20 19 18 17 16 15
Vi,SIF2 Vi,SIF2 Rcomp NC Vo,FM VS VAFC VVCO VVCO Vsw LF Cref GND NC
Pin 1, 2 3 4, 9, 16 5 6, 7 8 10 11 12 13 14 15 17 18 19 20, 21 22 23 24 25 26 27, 28
Symbol Vi, SIF1 Vsw GND CAGC Vi, VIF CAGC Rtop Itun Vo,vid NC NC NC Cref LF Vsw VVCO VAFC VS VO, FM NC Rcomp Vi, SIF2
Function SIF1 input (symmetrical) Input selector switch Ground SIF-AGC (time constant) VIF input (symmetrical) VIF-AGC (time constant) Take over point, tuner AGC Tuner AGC output current Video output Not connected Not connected Not connected Internal reference voltage Loop filter AFC switch VCO circuit AFC output Supply voltage Intercarrier output Not connected Offset compensation SIF 2 input (symmetrical)
Figure 2. Pinning
4 (14)
Rev. A3, 23FEb01
Preliminary Information
TDA4472
Absolute Maximum Ratings
Reference point Pin 4 (9, 16), unless otherwise specified Parameters Supply voltage Pin 23 SDIP28 package SO28 package Supply current Pin 23 Power dissipation SDIP28 package SO28 package Output currents Pins 12 and 24 External voltages Pins 1, 2, 5 to 8, 10, 12, 17, 18 and 24, 26 to 28 Pins 20 and 21 Pin 11 Pins 3, 19 and 22 Junction temperature Storage temperature Electrostatic handling *) all pins
*)
Symbol VS VS Is P P Iout
Value 9.0 6.0 93 840 560 5 +4.5 +3.5 +13.5 VS +125 25 to +125 "300
Unit V V mA mW mW mA V V V V °C °C V
Vext
Tj Tstg VESD
Equivalent to discharging a 200 pF capacitor trough a 0 W resistor.
Operating Range
Parameters Supply voltage range SDIP28 package SO28 package Ambient temperature Pin 23 VS VS Tamb 4.5 to 9.0 4.5 to 6.0 10 to +85 V V °C Symbol Value Unit
Thermal Resistance
Parameters Junction ambient, when soldered to PCB SDIP28 package SO28 package Symbol RthJA RthJA Maximum 55 75 Unit K/W K/W
Rev. A3, 23FEb01
5 (14)
Preliminary Information
TDA4472
Electrical Characteristics
VS = +5 V, Tamb = +25°C; reference point Pin 4 (9, 16), unless otherwise specified Parameters DC-supply Supply voltage SDIP28 SO28 Supply current VIF-input Input sensitivity, (RMS value) Input impedance Input capacitance VIF-AGC IF gain control range AGC capacitor Black level capacitor Switching voltage: VCR mode Switching current: VCR mode Tuner-AGC Available tuner-AGC current Allowable output voltage IF slip tuner AGC IF input signal for minimum take over point IF input signal for maximum take over point Variation of the take over point by temperature FPLL and VCO Max. oscillator frequency Vision carrier capture range Oscillator drift (free running) as function of temperature Test Conditions / Pins Pin 23 Symbol VS VS IS Pin 6-7 vin Rin Cin Pins 8 and 15 Gv 60 Pin 8 CAGC Pin 15 CBL See note 2 Vsw See note 2 Isw Pins 10 and 11 see note 3 Itun 1 V11 0.3 Current Itun: 10 to 90% GIF Rtop = 10 kW (Vtop = 4.5 vin V) Rtop = 0, (Vtop = 0.8 V) vin 40 For FPLL locked See note 1 See note 1 80 1.2 2 65 2.2 100 4.0 50 2 8 4 13.5 10 4 120 mVRMS kW pF dB mF nF V mA mA V dB mV mV 3 dB Min. 4.5 4.5 Typ. 5.0 5.0 85 Max. 9.0 5.5 93 Unit V V mA
Video output Output current
source sink
Output resistance Video output signal Difference of the video signals Sync. level Zero carrier level for neg. modulation, ultra white level Zero carrier level for pos. modulation, ultra black level Supply voltage influence on the ultra white and ultra black level Video bandwidth (3 dB)
Tamb = 55°C vin 2 VIF-AGC: Gv = 46 dB Pins 18, 20, 21 and 26 see note 4 For carrier generation fvco 70 fvco = 38.9 MHz, fcap ±1.5 ±2 Cvco = 8.2 pF See note 5, f/T amb = 55°C, Cvco = 8.2 pF, fvco = 38.9 MHz Pin 12 ±I12 2 See note 1 Rout Peak-to-peak value vo,vid 1.8 2.0 Between B/G and L vo,vid Vsync 1.2 V13 = VS VDC 3.4 V8 = 3 V V13 = 0 VDC 1.15 V8 = 3 V V/V 1 RL 1 kW, CL 50 pF B 6 8
MHz MHz 0.3 %
5 3 100 2.2 10
mA mA W Vpp % V V V %/V MHz
6 (14)
Rev. A3, 23FEb01
Preliminary Information
TDA4472
Parameters Video frequency response over the AGC range Differential gain error Differential phase error Intermodulation 1.07 MHz Video signal to noise ratio Residual vision carrier fundamental wave 38.9 MHz and second harmonic 77.8 MHz Lower limiting level Upper limiting level Ripple rejection AFC output Control slope Frequency drift by temperature Output voltage upper limit lower limit Output current AFC switch Control voltage: AFC "off" AFC "on" Switching current SIF inputs Input sensitivity (RMS value) Input impedance Input capacitance SIF-AGC IF gain control range AGC capacitor Intercarrier output-FM DC output voltage Output resistance Sound IF output voltage (5.5 MHz output voltage) Weighted signal to noise ratio: (CCIR 468) Test Conditions / Pins Symbol DG DP aIM S/N vres1 Vlim1 Vlim2 RR I/f Related to the picture carrier frequency VAFC IAFC Pin 19 VSW See note 7 ISW Pin 1-2, 27-28 vin Rin Cin Pin 5 Gv 60 CAGC see note 8 VDC Rout vout 180 65 10 2 150 250 dB mF V W mVRMS 0 3.5 ±100 80 1.2 2 0.8 VS V V mA mVRMS kW pF VS0.4 0.4 ±0.2 Min. Typ. Max. 2.0 5 5 Unit dB % deg dB dB mV 2 2 60 60 2
See note 6 Weighted, CCIR-567
52 56
10
Below sync level Above ultra white level See note 1, Pin 23/Pin 12 Pin 22
400 600 35 0.7 0.25
mV mV dB mA/kHz % V V mA
0.6
Output signal at Pin 24/25: 3 dB See note 1 See note 1
120
Pin 24 See note 1 vin = 10 mV Ref. signal: vin = 10 mV; FM dev. = ±27 kHz fmod = 1 kHz; tested with the double FM demod. U2860B; B/G modulated VIF signal Black screen: Channel 1/2 Grid pattern: Channel 1/2 Grey screen 50%: Channel 1/2 See note 1, Pin 23/Pin 24 Pin 3
350
S/N S/N S/N RR 35
60/58 54/52 60/57
dB dB dB dB
Ripple rejection SIF input selector switch
Rev. A3, 23FEb01
7 (14)
Preliminary Information
TDA4472
Parameters Test Conditions / Pins Control voltage: input 1 active See note 9 input 2 active Switching current Notes
1.) 2.) 3.) 4.)
Symbol VSW ISW
Min. 2.0 0
Typ.
Max. VS 0.8
±100
Unit V V mA
5.) 6.) 7.) 8.) 9.)
This parameter is given as an application information and not tested during production. In VCR mode the VIF- and SIF path is switched off. Adjustment of turn over point (delayed tuner AGC) with external resistor Rtop or external voltage Vtop possible. Resonance circuit of VCO (fo = 38.9 MHz): CVCO = 8.2 10 pF, Coil LVCO with unloaded Q-factor Qo w 60 for an oscillator voltage w 100 mVRMS at Pin 20 21 (e.g. TOKO coil 7 KM, 292 XNS - 4051Z) The oscillator drift is related to the picture carrier frequency, at external temperature-compensated LC circuit. a (1.07) = 20 log (4.43 MHz component/1.07 MHz component); a (1.07) value related to black-white signal input signal conditions: picture carrier = 0 dB, colour carrier = 6 dB, sound carrier = 24 dB Without control voltage at Pin 19 "AFC on" is automatically selected. Picture carrier PC = 38.9 MHz; sound carrier SC1 = 33.4 MHz, SC2 = 33.16 MHz; PC/SC1 =13 dB; PC/SC2 = 20 dB; PC unmodulated (equivalent to sync. peak level). Without control voltage at Pin 3 the SIF input 1 is automatically selected.
SIF 2
Loop comp.
Intercarrier (FM/NICAM) +VS
AFC AFC switch Loop filter LVCO 150 W 470 nF
10 k W NC 28 27 26 25 24 23 22 21
8.2 pF CVCO
CRef 2.2 mF 17 16 NC 15
20
19
18
1
2
3
4
5
6
7
8
9
10
11
12
13 NC
14 NC
10 mF SIF Input switch AGC (SIF) VIF
2.2 mF AGC (VIF)
10 k W
SIF 1 *)
Tuner delay
external L/C circuit (VCO 38.9 MHz) with TOKO coil 7KM, 292XNS 4051Z Figure 3. Test circuit
Tuner AGC
Video
8 (14)
Rev. A3, 23FEb01
Preliminary Information
94 9292
*)
Rev. A3, 23FEb01
Intercarrier (FM/NICAM) AFC AFC switch +12 V +5 V 51 kW 51 kW Offset comp. 10 nF 10 kW 8 28 25 23 27 26 24 22 7 6 1 5 SAW 1 SIF 1 S3 B/G SAW: VIF Input switch 10 mF AGC (SIF) 2 3 4 5 6 VIF 2.2 mF AGC (VIF) Tuner AGC 10 kW 7 8 9 10 11 12 13 NC 14 NC D/K SIF 2 NC 21 20 10 nF 8.2 pF SAW 2 *) LVCO CVCO 19 22 mF 10 nF S2 Loop filter 150 W CRef 470 nF 18 2.2 mF 17 16 NC 15
94 8721
External L/C circuit (VCO: 38.9 MHz) with TOKO coil 7KM, 292 XNS 4051Z
1
10 nF
50 W
2
10 nF
U4744B
3
Figure 4. Basic application circuit
IFin
Preliminary Information
4
SAW driver
TDA4472
Tuner
Video
9 (14)
TDA4472
Internal Pin Configuration
1, 27 2, 28 2kW 2k W 3V 20 k W 4.2 V
94 8521 94 8524
2 kW
2 kW 2.3 V
Figure 5. Sound IF inputs (Pin 1-2, 27-28) Figure 8. Video IF input (Pin 6-7)
3.5 V
94 8525
60 kW 3 10 kW
8
94 8522
Figure 6. Input selector switch (Pin 3)
Figure 9. VIF-AGC time constant (Pin 8)
3.5 V 5 6.5 kW 6 kW
94 8523 94 8526
Figure 7. SIF-AGC time constant (Pin 5)
Figure 10. Tuner AGC take over point (Pin 10)
10 (14)
Rev. A3, 23FEb01
Preliminary Information
TDA4472
94 8527
2.75 V
94 8532
Figure 11. Tuner AGC output (Pin 11)
Figure 14. Loop filter (Pin 18)
3.5 V
30 k W 19 2.6 mA 10.5 k W
94 8533 94 8528
Figure 15. AFC switch (Pin 19)
Figure 12. Video output (Pin 12)
7 kW
7 kW
3.5 V
94 8531
94 8534
Figure 13. Internal reference voltage (Pin 17)
Figure 16. VCO (Pin 20-21)
Rev. A3, 23FEb01
11 (14)
Preliminary Information
TDA4472
94 8538
3.5 V
10 kW 10 kW
94 8535
Figure 19. VCO offset compensation (Pin 26)
Figure 17. AFC output (Pin 22)
100 W 24 1 mA
94 8536
Figure 18. Intercarrier output (Pin 24)
12 (14)
Rev. A3, 23FEb01
Preliminary Information
TDA4472
Dimensions in mm
Package SDIP28
Dimensions in mm
27.5 27.1 4.8 4.2 0.9 3.3 0.53 0.43 23.114 1.778 0.35 0.25 12.2 11.0 8.7 8.5 10.26 10.06
1
technical drawings according to DIN specifications 13044
Package SO28
Dimensions in mm
18.05 17.80
9.15 8.65 7.5 7.3
2.35 0.4 1.27 28 16.51 15 0.25 0.10 0.25 10.50 10.20
technical drawings according to DIN specifications
1
14
13033
Rev. A3, 23FEb01
13 (14)
Preliminary Information
TDA4472
Ozone Depleting Substances Policy Statement
It is the policy of Atmel Germany GmbH to 1. Meet all present and future national and international statutory requirements. 2. Regularly and continuously improve the performance of our products, processes, distribution and operating systems with respect to their impact on the health and safety of our employees and the public, as well as their impact on the environment. It is particular concern to control or eliminate releases of those substances into the atmosphere which are known as ozone depleting substances (ODSs). The Montreal Protocol (1987) and its London Amendments (1990) intend to severely restrict the use of ODSs and forbid their use within the next ten years. Various national and international initiatives are pressing for an earlier ban on these substances. Atmel Germany GmbH has been able to use its policy of continuous improvements to eliminate the use of ODSs listed in the following documents. 1. Annex A, B and list of transitional substances of the Montreal Protocol and the London Amendments respectively 2. Class I and II ozone depleting substances in the Clean Air Act Amendments of 1990 by the Environmental Protection Agency (EPA) in the USA 3. Council Decision 88/540/EEC and 91/690/EEC Annex A, B and C (transitional substances) respectively. Atmel Germany GmbH can certify that our semiconductors are not manufactured with ozone depleting substances and do not contain such substances.
We reserve the right to make changes to improve technical design and may do so without further notice. Parameters can vary in different applications. All operating parameters must be validated for each customer application by the customer. Should the buyer use Atmel Wireless & Microcontrollers products for any unintended or unauthorized application, the buyer shall indemnify Atmel Wireless & Microcontrollers against all claims, costs, damages, and expenses, arising out of, directly or indirectly, any claim of personal damage, injury or death associated with such unintended or unauthorized use. Data sheets can also be retrieved from the Internet: http://www.atmelwm.com
Atmel Germany GmbH, P.O.B. 3535, D-74025 Heilbronn, Germany Telephone: 49 (0)7131 67 2594, Fax number: 49 (0)7131 67 2423
14 (14)
Rev. A3, 23FEb01
Preliminary Information