TDA8120B multistandard video and sound if system october 1993 . gain controlled if amplifier . vif operating frequency up to 50mhz . synchronous detector . white spot inverter . very low differential error . very low phase error . internal agc switch (b/g - l) . agc top. synch. for standard b/g . agc top white for standard l . quasi split sound for standard b/g . sound detector for standard l . video muting facility . separated sound output . operates without external gating pulse description the TDA8120B is a monolithic ic for tv video if and sound if amplification and demodulation that can operate with all the tv standards. the video if section can handle negative (b/g) or positive (l) modulated video signals by means of dc switching. dip24 (plastic package) order code : TDA8120B 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 24 23 22 21 11 12 af am out carrier tuning supply voltage 2nd if sound out (qss) gnd video output supply voltage agc time constant carrier tuning v s1 t 2v t 2s t 1s v s2 qss or am input gnd video if input standard switch agc time constant agc time constant agc time constant and video muting tuner agc output tuner agc delay t 1v 8120b-01.eps pin connections the sound if section acts as a quasi split sound (qss) subsystem in b/g transmission and allows a second sound if with high rejection of the video information. the dc switch can modify the sound if configura- tion to process am modulated sound signals (l). the TDA8120B is assembled in a 24 pin dual in line power package. 1/6
22 18 16 17 11 12 4 9 14 13 10 19 20 21 23 24 1 5 6 23 8 7 15 video section sound section ssw ssw ssw ssw ssw standard switch (b/g or l) limiter phase shifter (0 or 180 ) voltage regulation white spot inv. noise invert video preamp. video demod. and buffer vif amp (3 stages) agc amplif. and agc delay top sync clamp or top white clamp min. video detector 2nd sif demod. limiter and phase shifter (90 ) buffer 1st sif amp. (3 stages) agc amplif. and agc delay am or agc detector limiter 8120b-02.eps block diagram absolute maximum ratings symbol parameter value unit v 4 ,v 9 supply voltage v s 15 v i 8 ,i 5 ,i 1 video out, qss out , af am out, dc output current 10 ma i 22 ,i 15 pin 22 and pin 15 input current 1 ma p tot total power dissipation (t amb =70 c) 2 w t stg ,t j storage and junction temperature 40 to 150 c v 14 voltage at pin 14 v s 8120b-01.tbl thermal data symbol parameter value unit r th jamb thermal resistance max 40 c/w 8120b-02.tbl TDA8120B 2/6
electrical characteristics (v s = 12v, t amb =25 c) symbol parameter test conditions min. typ. max. unit video if section v i =10mv rms (black field), f o = 38.9mhz ; unless otherwise specified v s supply voltage (pins 4 and 9) 10.8 12 13.2 v i s supply current v i = 0 120 ma v 8h top white level v i =0,r l = 1.5k w 5.5 6 6.5 v v 8l top synchronous level 2.7 3 3.3 v v 8 video output b/g modulation depth, d = 90%, r l = 1.5k w 2.2 3 3.4 v pp v 8 video output l r l = 1.5k w , m = 100% 2.2 3 3.4 v pp d v 8 video output variation between standards b/g and l m = 100% 2% i 8 output current r l = 1.5k w 4ma i 8 input current 2 ma i 14 tuner agc current capability 4.5 ma s/n signal to noise ratio b = 5mhz, d = 90% 50 db d v i agc range d v 8 = 1db, d = 90% 60 db b bandwidth d v 8 = 3db, d = 90% 7 mhz v 1617 input sensitivity for full output signal d = 90% 50 m v v 8 carrier leakages f o = 38.9mhz f o = 77.8mhz 20 50 mv mv dg differential gain subcarrier modulated staircase video signal, d = 90% 10 % d f differential phase subcarrier modulated staircase video signal, d = 90% 10 degree d im intermodulation product 1.07mhz video carrier relative level = 0db chroma subcarrier relative level = 3.2db sound carrier relative level = 20db 50 db r i input resistance (between pins 16 and pin 17) 1.5 k w c i input capacitance (between pins 16 and pin 17) 2pf quasi split sound channel or french sound channel (see notes 1 and 2) v 2021 input sensitivity for full output signal (between pins 20 and 21) r channel missing 50 m v d v i agc range d v 5 = 1db, r channel missing 60 db v 5 output voltage standard b/g r l = 600 w , ac coupled, f o = 5.5mhz 100 mv rms i 5 output current 2.5 ma z 5 small signal output impedance (qss) f o = 5.5mhz or f o = 5.74mhz 50 k w r i input resistance (between pin 21 and pin 20) 1.5 k w c i input capacitance (between pin 21 and pin 20) 2pf s/n noise ratio qss (after sif limitation and fm demodulation) f o = 5.50mhz f o = 5.74mhz channel r or channel l switched off f m = 1khz, d f= 30khz carrier modulated with syncs. pulses only. ccir 468-2 recommendant 60 58 db v 1 output voltage standard l 0.58 0.7 1 v rms i 1 output current 2.5 ma z 1 af output impedance (l) 50 w s/n noise ratio am standard l b n = 20khz 46 db 8120b-03.tbl TDA8120B 3/6
c1 123456 24 23 22 21 20 19 18 7 17 16 89 15 10 11 14 12 13 c2 c3 c4 l2 38.9 or 32.7mhz video out 5.50mhz out 5.74mhz out af am out 38.9mhz v s v 15 v 22 TDA8120B c7 c6 c5 vif qss (b/g) or am (l) saw filter if in agc out p1 agc delay adj. c8 8120b-03.eps test circuit electrical characteristics (continued) symbol parameter test condition s min. typ. max. unit quasi split sound channel or french sound channel (see notes 1 and 2) d distorsion 2% v 22 b/g operation l operation 2 0 5 0.8 v v v 15 video muting 8 v s v 8120b-04.tbl notes : 1. quasi split sound channel video carrier relative level = 0db f = 38.9mhz d f = 0 sound carrier relative level = 13db (mono or l) f = 33.4mhz sound carrier relative level = -20db (r) f = 33.16mhz v i = 10mv video carrier modulated with syncs ; v 22 = 2v, unless otherwise specified. 2. french sound channel v i = 10mv (carrier level) ; f o = 39.2mhz ; f m = 1khz ; m = 80% ; v 22 = 0.8v, unless otherwise specified. TDA8120B 4/6
the TDA8120B (see block diagram) consists of a video section and a sound section. the integration of both sections on the same chip requires a high isolation at if frequencies. this is achieved by physically separating the two sections, with sepa- rate power supplies and ground pins. in addition, special care has been taken in the choice of pad positions for the if inputs and sound/video outputs. the video section consists of three ac-coupled if stages with more than 60db agc range, flat ampli- tude/frequency response from 10 to 85mhz and linearized phase slope from 30 to 50mhz. video carrier regeneration is performed by a tuned limiter. the carrier is then applied to the video demodulator through a special circuit which switches the carrier phase from 0 to 180 so that the video polarity can be maintained constant when the standard switches from b/g to l. a noise inverter and a white spot inverter are included to eliminate ultra-black and white pulses. a top sync or a top white clamping circuit and a minimum dc video component detector are imple- mented by two double comparators the charac- teristics of which may be controlled by an external control input to adapt to the modulation type for each standard. the voltage at the output of the two comparatorsis memorized by an externalcapacitor and used to drive the agc network, which allows an input regulation of the video carrier from less than 100 m v to 100mv. a delayed control storage with current output for the turner agc completes the video section. the sound section consists of three if stages with the same characteristicsas the video if stages and an identical network to control and set the gains of the three if amplifiers. the output of the third if stage feeds the am/agc detector and the qss section. the am/agc detector consists of a wideband limiter for am sound regeneration or video carrier regeneration used to feed the synchronous multi- plier and consequently to obtain the am demodu- lated audio signal. in addition, a dc voltage proportional to the peak-to-peak value of the video carrier is produced. two comparators complete the sound agc loop. the subsequent qss section consists of a refer- ence amplifier tuned to the video if which buffers a wideband limiter to reject completely the video am information withou t introducing incidental phase modulation (ipm). following the limiter there are a 90 phase shifter and a linear-to-logarithmic converter which drives a linear multiplier as a demodulator for the intercar- rier 2nd sound if. this quadrature multiplier rejects all video components transmitted in dsb that is low frequency components of the video signal. in addition to the sound and video sections, the TDA8120B includes a block for standard switching (b/g or l) controlled by a ttl-compatible input. circuit operation TDA8120B 5/6
information furnished is believed to be accurate and reliable. however, sgs-thomson microelectronics assumes no responsibility for the consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from its use. no licence is granted by implication or otherwise under any patent or patent rights of sgs-thomson microelectronics. specifications mentioned in this publication are subject to change without noti ce. this publication supersedes and replaces all information previously supplied. sgs-thomson microelectronics products are not authorized for use as critical components in life support devices or systems without express written approval of sgs-thomson microelectronics. ? 1994 sgs-thomson microelectronics - all rights reserved purchase of i 2 c components of sgs-thomson microelectronics, conveys a license under the philips i 2 c patent. rights to use these components in a i 2 c system, is granted provided that the system confo rms to the i 2 c standard specifications as defined by philips. sgs-thomson microelectronics group of companies australia - brazil - china - france - germany - hong kong - italy - japan - korea - malaysia - malta - morocco the netherlands - singapore - spain - sweden - switzerland - taiwan - thailand - united kingdom - u.s.a. 24 i a1 l b2 e d e3 f b1 e 13 112 b pm-dip24.eps package mechanical data 24 pins - plastic dip dimensions millimeters inches min. typ. max. min. typ. max. a1 0.63 0.025 b 0.45 0.018 b1 0.23 0.31 0.009 0.012 b2 1.27 0.050 d 32.2 1.268 e 15.2 16.68 0.598 0.657 e 2.54 0.100 e3 27.94 1.100 f 14.1 0.555 i 4.445 0.175 l 3.3 0.130 dip24.tbl TDA8120B 6/6
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