Click here to load reader

VIF-PLL demodulator and FM-PLL · PDF file•True synchronous demodulation with active carrier ... VESD electrostatic handling for all pins ... VIF-PLL demodulator and FM-PLL detector

  • View
    233

  • Download
    9

Embed Size (px)

Text of VIF-PLL demodulator and FM-PLL · PDF file•True synchronous demodulation with active...

  • DATA SHEET

    Preliminary specificationFile under Integrated Circuits, IC02

    July 1994

    INTEGRATED CIRCUITS

    TDA9800VIF-PLL demodulator and FM-PLLdetector

  • July 1994 2

    Philips Semiconductors Preliminary specification

    VIF-PLL demodulator and FM-PLL detector TDA9800

    FEATURES

    Suitable for negative vision modulation Applicable for IF frequencies of 38.9 MHz, 45.75 MHz

    and 58.75 MHz

    Gain controlled wide band VIF amplifier (AC coupled) True synchronous demodulation with active carrier

    regeneration (ultra-linear demodulation, goodintermodulation figures, reduced harmonics andexcellent pulse response)

    Peak sync AGC for negative modulation Video amplifier to match sound trap and sound filter

    AGC output voltage for tuner; adjustable take-over point(TOP)

    AFC detector without extra reference circuit Alignment-free FM-PLL detector with high linearity Stabilizer circuit for ripple rejection and to achieve

    constant output signals

    5 to 8 V positive supply voltage range, low powerconsumption (300 mW at +5 V supply voltage).

    GENERAL DESCRIPTION

    The TDA9800 is a monolithic integrated circuit for visionand sound IF signal processing in TV and VTR sets.

    QUICK REFERENCE DATA

    ORDERING INFORMATION

    Note

    1. SOT146-1; 1996 December 6.

    2. SOT163-1; 1996 December 6.

    SYMBOL PARAMETER MIN. TYP. MAX. UNIT

    VP positive supply voltage (pin 20) 4.5 5 8.8 V

    IP supply current 51 60 69 mA

    Vi IF vision IF input signal sensitivity (RMS value, pins 1 and 2) 50 90 Vmaximum vision IF input signal (RMS value, pins 1 and 2) 70 150 mV

    Gv IF gain control 64 70 73 dB

    Vo CVBS CVBS output signal on pin 7 (peak-to-peak value) 1.7 2.0 2.3 V

    B 3 dB video bandwidth on pin 7 6 8 MHzS/N (W) signal-to-noise ratio weighted; for video 56 59 dB0.92/1.1 intermodulation attenuation 56 62 dB2.76/3.3 56 62 dBH suppression of harmonics in video signal 35 40 dBVo AF maximum AF output signal for THD < 1.5% (RMS value, pin 9) 0.8 VTamb operating ambient temperature 20 +70 C

    EXTENDED TYPENUMBER

    PACKAGE

    PINS PIN POSITION MATERIAL CODE

    TDA9800 20 DIL plastic SOT146(1)

    TDA9800T 20 mini-pack plastic SOT163A(2)

  • July 1994 3

    Philips Semiconductors Preliminary specification

    VIF-PLL demodulator and FM-PLL detector TDA9800

    Fig.1 Block diagram.

    handbook, full pagewidth

    VP = 5 V (9 V)

    18

    1

    2

    20 1617

    INTERNALREFERENCE

    VOLTAGE

    TRAVELLINGWAVE

    DIVIDERAFC

    AGCDETECTOR

    VCO

    3-STAGEIF-AMPLIFIER

    FREQUENCYDETECTORAND PHASEDETECTOR

    9

    10

    15

    7

    IFAGC

    12

    TUNERAGC

    tuner AGCoutput

    takeoverpoint

    TDA9800

    VIDEODEMODULATOR

    VIDEOAMPLIFIER

    193 14 11138

    BUFFER AND NOISE

    CLIPPING

    FM-PLL

    AFAMPLIFIER

    1 V (p-p)

    4

    5

    6

    soundMUTE

    IF input

    SOUNDTRAP

    SOUNDFILTER

    soundmute

    video andintercarrier

    n.c.

    MED329

    TPLL

    2fPC

    Vi PC

    VP VCO2 VCO1 AFC

    Vo AF

    CAF

    CAF

    Vo CVBS

    2 V (p-p)

    Vi ICVi(vid)Vo(vid)MUTECAGC

    CAGC

    TAGCTOP

    CCS

    Vi VIF2

    Vi VIF1

    GND

  • July 1994 4

    Philips Semiconductors Preliminary specification

    VIF-PLL demodulator and FM-PLL detector TDA9800

    PINNING

    SYMBOL PIN DESCRIPTION

    Vi IF 1 vision IF differential input signal

    2

    TADJ 3 tuner AGC take-over adjust (TOP)

    ADJ 4 phase detector adjustMUTE 5 sound mute switch

    TPLL 6 PLL time constant of phase detector

    Vo CVBS 7 CVBS (positive) output signal

    n.c. 8 not connected

    Vo AF 9 audio frequency output signal

    CAF 10 decoupling capacitor of audio frequency amplifier

    Vi IC 11 sound intercarrier input signal

    TAGC 12 tuner AGC output

    Vo VID 13 video and sound intercarrier output signal

    Vi VID 14 video input signal to buffer amplifier

    AFC 15 automatic frequency control output

    VCO1 16 VCO reference circuit for 2 fPCVCO2 17

    GND 18 ground (0 V)

    CAGC 19 AGC capacitor

    VP 20 positive supply voltage

    Fig.2 Pin configuration.

    handbook, halfpageVi VIF1

    Vi VIF2

    TOP

    CCS

    MUTE

    TPLL

    Vo CVBS

    n.c.

    Vo AF

    CAF

    VP

    CAGC

    GND

    VCO2

    AFC

    Vi(vid)

    VCO1

    Vo(vid)

    TAGC

    Vi IC

    1

    2

    3

    4

    5

    6

    7

    8

    9

    10 11

    12

    20

    19

    18

    17

    16

    15

    14

    13

    TDA9800

    MED330

  • July 1994 5

    Philips Semiconductors Preliminary specification

    VIF-PLL demodulator and FM-PLL detector TDA9800

    FUNCTIONAL DESCRIPTION

    Vision IF input

    The vision IF amplifier consists of three AC-coupleddifferential amplifier stages; each stage comprises acontrolled feedback network by means of emitterdegeneration.

    IF and tuner AGC

    The automatic control voltage to maintain the video outputsignal at a constant level is generated according to thetransmission standard. Since the TDA9800 is suitable fornegative modulation only the peak-sync level is detected.The AGC detector charges and discharges the capacitoron pin 19 to set the IF gain and the tuner gain. The AGCcapacitor voltage is transferred to an internal IF controlsignal, and is fed to the tuner AGC to generate the tunerAGC output current on pin 12 (open-collector output). Thetuner AGC voltage take over point is adjusted on pin 3.This allows the tuner and the IF SAW filter to be matchedto achieve the optimum IF input level.

    Frequency detector, phase detector and videodemodulator

    The IF amplifier output signal is fed to a frequency detectorand to a phase detector. During acquisition the frequencydetector produces a DC current which is proportional to thefrequency difference between the input and the VCOsignal. After frequency lock-in the phase detectorproduces a DC current proportional to the phasedifference between the VCO and the input signal. Via theloop filter the DC current of either frequency detector orphase detector is converted into a DC voltage, whichcontrols the VCO frequency.The video demodulator is a linear multiplier, designed forlow distortion and wide bandwidth. The vision IF inputsignal is multiplied by the in-phase component of the VCOoutput. The demodulated output signal is fed via anintegrated low-pass filter (fg = 12 MHz) to the videoamplifier for suppression of the carrier harmonics.

    VCO and travelling wave divider

    The VCO operates with a symmetrically-connectedreference LC-circuit, operating at double vision carrierfrequency. Frequency control is performed by an internalvaricap diode. The voltage to set the VCO frequency to theactual frequency of double vision carrier frequency, is alsoamplified and converted for the AFC output current.The VCO signal is divided-by-two in a travelling wavedivider, which generates two differential output signals

    with 90 degree phase difference independent offrequency.

    Video amplifier, buffer and noise clipping

    The video amplifier is a wide bandwidth operationalamplifier with internal feedback. A nominal positivemodulated video signal of 1 V (p-p) is present on thecomposite video output (pin 13). The input impedance ofthe 7 dB wideband buffer amplifier (with internal feedback)is suitable for ceramic sound trap filters. The CVBS output(pin 7) provides a positive video signal of 2 V (p-p). Noiseclipping is provided internally.

    Sound demodulation

    The FM sound intercarrier signal is fed to pin 11 andthrough a limiter amplifier before it is demodulated. Thisachieves high sensitivity and high AM suppression. Thelimiter amplifier consists of seven internal AC-coupledstages, minimizing the DC offset.The FM-PLL demodulator consists of an RC-oscillator,loop filter and phase detector. The oscillator frequency islocked on the FM intercarrier signal from the limiteramplifier. As a result of this locking, the RC-oscillator isfrequency-modulated.The modulating signal voltage (AF signal) is used tocontrol the oscillator frequency. By this, the FM-PLLoperates as an FM demodulator.The audio frequency amplifier with internal feedback isdesigned for high gain and high common mode rejection.The low-level AF signal output from the FM-PLLdemodulator is amplified and buffered in a low-ohmicaudio signal output stage (pin 9). An external decouplingcapacitor on pin 10 removes the DC voltage from the audioamplifier input.By using the sound mute switch (pin 5) the AF amplifier isset to mute state.

  • July 1994 6

    Philips Semiconductors Preliminary specification

    VIF-PLL demodulator and FM-PLL detector TDA9800

    LIMITING VALUESIn accordance with the Absolute Maximum Rating System (IEC134).

    Notes

    1. Supply current IP = 69 mA at Tamb = +70 C.2. Equivalent to discharging a 200 pF capacitor through a 0 series resistor (negative and positive voltage).

    THERMAL RESISTANCE

    SYMBOL PARAMETER MIN. MAX. UNIT

    VP supply voltage (pin 20) for a maximum chip temperature (note 1)

    SOT146 at +120 C 0 8.8 VSOT163A at +100 C 0 5.5 V

    VI voltage on pins 1, 2, 7, 11, 13, 14, 15 and 19 0 VP V

    ts max short-circuit time 10 sV12 tuner AGC output voltage 13.2 VTstg storage temperature range 25 +150 CVESD electrostatic handling for all pins (note 2) 300 V

    SYMBOL PARAMETER THERMAL RESISTANCE

    Rth j-a from junction to ambient in free air

    SOT146 73 K/W

    SOT163A 85 K/W

  • July 1994 7

    Philips Semiconductors Preliminary specification

    VIF-PLL demodulator and FM-PLL detector TDA9800

    CHARACTERISTICSThe