View KK34118_3171989.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

technical data KK34118 voice switched speakerphone circuit the kk 34118 voice switched speakerphone circuit incorporates the n ecessary am p lifiers, atten u a to rs, lev e l d e tecto r s, an d co n t ro l alg o r ith m to form the heart of a high quality ha nds-free speakerphone system . included are a m i crophone am pl i f i e r wi t h adjust abl e gai n and m u te cont rol , transm it and receive attenuators which operate in a com p lem e ntary m a nner, l e vel det ect ors at bot h i nput and out put of bot h at t e nuat o rs, and background noise m onitors for both th e transm it and receive channels. a di al tone det ect or prevent s t h e di al t one from bei ng at t e nuat e d by t h e receive background noise m onitor circ uit. also included are two line dri v er am pl i f i e rs whi c h can be used t o form a hy bri d net w ork i n co n j u n c tio n with an ex tern al co u p lin g tran sfo r m e r. a h i g h p a ss filter can be used to filter out 60 hz noise in the receive channel, or for other filterin g fu n c tio n s . a ch ip disab l e p i n p e rm its p o w erin g d o w n th e en tire ci rcui t t o conserve power on l ong l oops where l oop current i s at a mi n i mu m. ordering information kk 34118n plastic kk 34118dw soic t a = -25 to 7 0 c for all packages the kk 34118 may be operated from a power supply, or it can be powered from t h e t e l e phone l i n e, requi ri ng t y pi cal l y 5.0 m a . the KK34118 can be interfaced directly to tip and ri ng (through a coupling transform e r) for st and-al one operat i on, or i t can be used i n conjunct i on wi t h a handset speech network and or other features of a feature phone. pin assignment ? im proved at t e nuat o r gai n r a nge: 52 db b e t w een transm i t and receive ? low vol t a ge operat i on for li ne-powered appl i cat i ons (3.0-6.5 v) ? 4 po in t sig n a l sen s in g fo r im p r o v e d sen s itiv ity ? background noise monitors for bo th transm it and receive paths ? m i crophone am pl i f i e r gai n set by ext e rnal r e si st ors - m u t e funct i on incl uded ? c h i p di sabl e for act i v e st andby operat i on ? on bo ard filter pin n e d - ou t fo r user defin e d fu n c tio n ? dial tone detector to inhibit r eceive idle mode during dial tone presence 1
KK34118 simplified block diagram functional description introduction the fundam e nt al di fference bet w een t h e operat i on of a speakerphone and a handset i s t h at of hal f-dupl ex versus ful l - dupl ex. the handset i s ful l dupl ex si nce conversat i on can occur i n bot h di rect i ons (t ransm i t and receive) sim u ltaneously. a sp eakerphone has higher gain l e vel s i n bot h pat h s, and at t e m p t i ng t o converse ful l duplex results in oscillatory problem s due to the loop t h at exi s t s wi t h i n t h e sy st em . the l oop i s form ed by t h e receive and transm it paths, the hybrid, and the acoustic coupl i ng (speaker t o m i crophone). the onl y pract i cal and econom i cal sol u t i on used t o dat a i s t o desi gn t h e speakerphone t o funct i on i n a hal f dupl ex m ode - i . e., onl y one person speaks at a t i m e, whi l e t h e ot her l i s t e ns. to achieve this requires a circuit which can detect who is talk in g , switch o n th e ap p r o p r iate p a th (tran s m it o r receive), and switch off (attenua te) the other path. in this way , t h e l oop gai n i s m a i n t a i n ed l e ss t h an uni t y . w h en the talkers exchange function, th e circu it m u st q u i ck ly d e tect th is, an d switch th e circu it ap p r o p r iately. by providing speech level detectors, the circuit operates in a ?hand-free? m ode, elim inating the need for a ?push-to- talk ? switch . the handset , by t h e way , has t h e sam e l oop as t h e speakerphone. b u t si nce t h e gai n s are consi d erabl y lower, and since the acoustic coupling from the earpiece to the m outhpiece is alm o st non- existent (the receiver is norm a lly held against a person?s ear), oscillations don?t occur. the kk 34118 provides the nece ssary level detectors, at t e nuat o rs, and swi t c hi ng cont rol for a properl y operating speakerphone. the de tection sensitivity and tim in g are ex tern ally co n t ro llab l e. ad d itio n a lly, th e kk3 4118 provides background noise monitors which m a k e th e circu it in sen s itiv e to ro o m an d lin e n o i se, hy bri d am pl i f i e rs for i n t e rfaci ng t o ti p and r i ng, t h e m i crophone am pl i f i e r, and ot her associ at ed funct i ons. attenuators the transm it and receive attenuators are com p l e m e nt ary i n funct i on, i . e., when one i s at m a xi m u m gai n (+6.0 db ), t h e ot her i s at m a xi m u m at t e nuat i on (-46 db ), and vi ce versa. they are never bot h ful l y on or bot h ful l y off. the sum of t h ei r gai n s rem a i n s const a nt (wi t h i n a nom i n al error band of 0.1 db ) at a t y pi cal val u e of -40 db . thei r purpose i s t o cont rol t h e transm it and receive paths to provide the half-duplex operat i on requi red i n a speakerphone. the at t e nuat o rs are non-i nvert i ng, and have a -3.0 db (from m a x gain) frequency of 100 khz. the i nput im pedance of each attenuator (txi and rxi) is nom i n al l y 10 k ? (see fi gure 1), and t h e i nput si gnal shoul d be l i m i t e d t o 350 m v rm s (990 m v p-p) t o prevent di st ort i on. that m a xi m u m 2
recom m e nded i nput si gnal i s i ndependent of t h e vol um e cont rol set t i ng. the di ode cl am p on t h e i nput s l i m i t s t h e i nput swi ng, and t h erefore t h e m a xi m u m negat i v e out put swin g . th is is th e reaso n fo r v rxol and v txol speci fi cat i on bei ng defi ned as they are in the electrical c h aract eri s t i c s. the out put i m pedance i s <10 ? u n til th e output current lim it (typically 2.5 m a ) is reached. figure 1. attenuator input stage the at t e nuat o rs are cont rol l e d by t h e si ngl e out put of th e co n t ro l blo c k , wh ich is m easu r ab le at th e c t pi n (pin 1 4 ) . w h en th e c t pin is at +240 m illivolts with respect to v b , the circuit is in the receive m ode (receive atten u a to r is at +6 .0 d b ). w h en th e c t pi n i s at - 240 m illivolts with respect to v b , th e circu it is in th e tran sm it m o d e (tran s m it atten u a to r is at +6 .0 d b ). th e circu it is in an id le m o d e wh en th e c t v o ltag e is eq u a l to v b , cau sin g th e atten u a to rs? g a in s to b e h a lfway b e tween their fully on and fully o ff positions (-20 db each). m oni t o ri ng t h e c t v o ltag e (with resp ect to v b ) is th e m o st di rect m e t hod of m oni t o ri ng t h e ci rcui t ? s m ode. the i nput s t o t h e c ont rol b l ock are seven: 2 from t h e com p arat ors operat e d by t h e l e vel det ect ors, 2 from t h e background noi se m oni t o rs, t h e vol um e cont rol , t h e di al - t one det ect or, and t h e agc ci rcui t . these seven i nput s are descri bed bel o w. level detectors there are four level detectors - two on the receive si de and t w o on t h e t r ansm i t si de. r e fer t o fi gure 2 - t h e t e rm s i n parent heses form one sy st em , and t h e ot her t e rm s form t h e second sy st em fi gure 2. l e vel detectors each lev e l d e tecto r is a h i g h g a in am p lifier with back-t o-back di odes i n t h e feedback pat h , resul t i ng i n non-l i n ear gai n , whi c h perm i t s operat i on over a wi de dynam i c range of speech levels. the sensitivity of each lev e l d e tecto r is d e term in ed b y th e ex tern al resisto r an d capacitor at each input (tli1, tli2, rli1, and rli2). each out put charges an ext e rnal capaci t o r t h rough a di ode and l i m i t i ng resi st or, t hus provi di ng a dc represent a t i on of t h e i nput ac si gnal l e vel . the out put s have a qui ck ri se t i m e (det erm i ned by t h e capaci t o r and an i n t e rnal 350 ? resistor), and a slow decay tim e set by an internal current source and the capaci t o r. the capaci t o rs on t h e four out put s shoul d have t h e sam e val u e ( 10%) t o prevent t i m i ng probl em s. referring to figure 8, on th e receive side, one level detector (rli1) is at the receive input receiving the sam e si gnal as at ti p and r i ng, and 3 KK34118
t h e ot her (r li2) i s at t h e out put of the speaker am plifier. on th e tran sm it sid e , o n e lev e l d e tecto r (tli2 ) is at th e out put of t h e m i crophone am pl i f i e r, whi l e t h e ot her (tli1) i s at t h e hy bri d out put . out put s r l o1 and tlo1 feed a com p arat or, t h e out put of whi c h goes t o t h e at t e nuat o r c ont rol b l ock. li kewi se, out put s r l o2 and tlo2 feed a second com p arat or whi c h al so goes t o t h e at t e nuat o r c ont rol b l ock. the t r ut h t a bl e for t h e effect s of t h e l e vel det ect ors on t h e c ont rol b l ock i s gi ven i n t h e sect i on descri bi ng t h e c ont rol b l ock. background noise monitors the purpose of t h e background noi se m oni t o rs i s t o distinguish speech (which consists of bursts) from background noi se (a rel a t i v el y const a nt si gnal l e vel ) . there are t w o background noi se m oni t o rs - one for t h e receive path and one for the transm it path. referring to figure 2, the receive background noise m onitor is operat e d on by t h e r l i1-r lo1 l e vel det ect or, whi l e t h e t r ansm i t background noi se m oni t o r i s operat e d on by t h e tli2-tlo2 l e vel det ect or. they m oni t o r t h e background noi se by st ori ng a dc vol t a ge represent a t i v e o f th e resp ectiv e n o i se lev e ls in cap acito rs at cpr an d c p t. the vol t a ges at t h ese pi ns have sl ow ri se t i m es (determ i ned by the external rc), but fast decay tim es. if t h e si gnal at r l i1 (or tli2) changes sl owl y , t h e vol t a ge at cpr (o r cpt) will rem a in m o re p o s itiv e th an th e vol t a ge at t h e non-i nvert i ng i nput of t h e m oni t o r?s output com p arator. w h en speech is present, the voltage on the non-inverting input of the com p arator will rise qui cker t h an t h e vol t a ge at t h e i nvert i ng i nput (due t o t h e burst characteristic of sp eech), causing its output to change. thi s out put i s sensed by t h e at t e nuat o r c ont rol b l ock. the 36 m v offset at t h e com p arat or?s i nput keeps t h e com p arator from changing state unless the speech level exceeds the background noise by 4.0 db . the t i m e const a nt of t h e ext e rnal r c ( 4.7 seconds) det e rm i n es t h e response t i m e t o background noi se vari at i ons volume control the vol um e cont rol i nput at vlc (pi n 13) i s sensed as a v o ltag e with resp ect to v b . the vol um e cont rol affects the attenuators only in the receive m ode. it has no effect in th e id le o r tran sm it m o d e s. w h en in the receive m ode, the gain of the receive atten u a to r will b e +6 .0 d b , an d th e g a in o f th e tran sm it atten u a to r will b e -4 6 d b o n l y wh en vlc is eq u a l to v b . as vlc is reduced below v b , the gain of the receive attenua tor is reduced, and the gain o f th e tran sm it atten u a to r is in creased su ch th at th eir su m rem a i n s const a nt . c h angi ng t h e vol t a ge at vlc changes th e v o ltag e at c t (see t h e at t e nuat o r c ont rol b l ock sectio n ) , wh ich in tu rn co n t ro ls th e atten u a to rs. the vol um e cont rol set t i ng does not affect t h e m a xi m u m at t e nuat o r i nput si gnal at whi c h not i ce abl e di st ort i on occurs. the bi as current at vlc i s t y pi cal l y 60 na out of t h e pi n, and does not vary si gni fi cant l y wi t h t h e vlc vol t a ge or wi t h v cc . dial tone detector the di al t one det ect or i s a com p arat or wi t h one si de connected to the receive input (rxi) and the other input connected to v b with a 15 m v offset (see figure 3). if the circuit is in the recei ve m ode, and the incom i ng si gnal i s great er t h an 15 m v (10 m v rm s), t h e com p arator?s output will cha nge, disabling the receive idle m ode. the receive attenuator will then be at a set t i ng det e rm i n ed sol e l y by t h e vol um e cont rol . th e p u r p o s e o f th is circu it is to p r ev en t th e d i al to n e (whi ch woul d be consi d ered as cont i nuous noi se) from fadi ng away as t h e ci rcui t woul d have t h e t e ndency t o switch to the idle m ode. by disabling the receive idle m ode, the dial tone rem a ins at the norm a lly expected full lev e l. fi gure 3. di al t o ne detector agc the agc circuit affects th e circu it o n l y in th e receive m ode, and only when the supply voltage (v cc ) is less th an 3 . 5 v o lts. as v cc falls b e lo w 3 . 5 v o lts, th e g a in of the receive attenuator is reduced. the transm it path atten u a tio n ch an g e s su ch th at th e su m o f th e tran sm it and receive gains rem a ins constant. the purpose of t h i s feat ur e is to reduce the power (and current ) used by t h e sp eaker when a line-powered speakerphone i s connect ed t o a l ong l i n e, where t h e av ailab l e p o w er is lim ited . by red u c in g th e sp eak er power, t h e vol t a ge sag at v cc i s cont rol l e d, prevent i ng possi bl e errat i c operat i on. 4 KK34118
attenuator control block the at t e nuat o r c ont rol b l ock has t h e seven i nput s descri bed above: - the out put of t h e com p arat or operat e d by r l o2 and tlo2 (m i c rophone/ s peaker si de) - desi gnat e d c 1 . - the out put of t h e com p arat or operat e d by r l o1 and tlo1 (ti p / r i ng) si de) - desi gnat e d c 2 . - the out put of t h e t r ansm i t background noi se m oni t o r - desi gnat e d c 3 . - the output of the receive background noise m oni t o r - desi gnat e d c 4 . - the vol um e cont rol . - the di al t one det ect or. - the agc circuit. the si ngl e out put of t h e c ont rol b l ock cont rol s t h e two atten u a to rs. th e effect o f c1 -c4 is as fo llo ws: i n p u t s o u t p u t c 1 c 2 c 3 c 4 m o d e t x t x 1 x transm i t t x r x y y f a s t i d l e r x t x y y f a s t i d l e r x r x x 1 r e c e i v e t x t x 0 x s l o w idle t x r x 0 0 sl o w idl e r x t x 0 0 sl o w idl e rx r x x 0 slo w id le x = don?t c a re; y = c 3 and c 4 are not bot h 0 a defi ni t i on of t h e above t e rm s: 1) ?tran s m it? m ean s th e tran sm it atten u a to r is fu lly on (+6.0 db), and the receive attenuator is at m a x. at t e nuat i on (-46 db ). 2) ?receive? m eans both attenuators are controlled by the volum e control. at m a x. volum e, the receive atten u a to r is fu lly o n (6 .0 d b ), an d th e tran sm it at t e nuat o r i s at m a x. at t e nuat i on (-46 db ). 3) ?fast idle? m eans both transm it and receive speech are p r esen t in ap p r o x i m a tely eq u a l lev e ls. th e atten u a to rs are q u i ck ly switch e d (3 0 m s ) to id le until one speech level dom inates the other. 4) ?slow idle? m eans speech has ceased in both transm it and receive path. the attenuators are then sl owl y swi t c hed (1 second) t o t h e i d l e m ode. 5) switching to the full transm it or receive m odes from any other m ode is at the fast rate (30 m s ). a su m m a ry o f th e tru t h tab l e is as fo llo ws: 1) th e circu it will switch to tran sm it if: a) b o t h t r ansm i t l e vel det ect ors sense hi gher si gnal l e vel s relative to the respective r eceive level detectors (tli1 versus r l i1, tli2 versus r l i2), and b) t h e t r ansm i t background noi se m oni t o r i ndi cat es t h e presence of speech. 2) the circuit will switch to r eceive if: a) both receive lev e l d e tecto r s sen s e h i g h e r sig n a l lev e ls relativ e to th e respective transm it level det ectors, and b) the receive background noi se m oni t o r i ndi cat es t h e presence of speech. 3) th e circu it will switch to th e fast id le m o d e if th e l e vel det ect ors di sagree on t h e rel a t i v e st rengt hs of t h e si gnal l e vel s , and at l east one of t h e background noi se m onitors indicates speech. for exam ple, referring to the expanded logi c di agram (fi gure 8), i f t h ere i s suffi ci ent si gnal at t h e m i crophone am p out put (tli2) t o overri de t h e speaker si gnal (r li2), and t h ere i s sufficient signal at the receive input (rli1) to override t h e si gnal at t h e hy bri d out put (tli1), and ei t h er or bot h background m onitors indicate speech, then the circuit will be in the fast idle m ode. two conditions which can cau se th e fast id le m o d e to occur are a) when both talk ers are attem p tin g to g a in co n t ro l o f th e system b y talk in g at th e sam e tim e, an d b ) wh en o n e talk er is in a very noi sy envi ronm ent , forci ng t h e ot her t a l k er t o cont i nual l y overri de t h at noi se l e vel . in general , t h e fast id le m o d e will o ccu r in freq u e n tly. 4) th e circu it will switch to th e slo w id le m o d e wh en a) both talkers are quiet (no speech present), or b) when one talker?s speech level is continuously overriden by noise at the other speaker?s location. th e tim e req u i red to switch th e circu it b e tween transm it, receive, fast idle and slow idle is determ ined in part by t h e com ponent s at t h e c t pi n (pi n 14). a sch e m a tic o f th e c t ci rcui t r y i s shown i n fi gure 4 and o p e rates as fo llo ws: - r t i s t y pi cal l y 120 k ? , and c t t y pi cal l y 5.0 f. - to switch to the receive m ode, i 1 is tu rn ed o n (i 2 is off), chargi ng t h e ext e rnal capaci t o r t o +240 m v above v b . (an internal clam p prevents further charging of the capacitor.) - to switch to th e tran sm it m o d e , i 2 is tu rn ed o n (i 1 is off) bringing down the voltage on the capacitor to - 240 m v wi t h respect t o v b . - to switch to id le q u i ck ly (fast id le), th e cu rren t sources are turned off, and the internal 2.0 k ? resisto r is switch e d in , d i sch a rg in g th e cap acito r to v b wi t h a t i m e const a nt = 2.0 k ? x c t . - to switch to id le slo w ly (slo w id le), th e cu rren t sources are turned off, the switch at the 2.0 k ? resi st or i s open, and t h e capaci t o r di scharges t o v b t h rough t h e ext e rnal resi st or r t with a tim e co n s tan t = r t x c t . 5 KK34118
figure 4. ct attenuator control block circuit microphone amplifier the m i crophone am pl i f i e r (pi n 10, 11) has t h e non- i nvert i ng i nput i n t e rnal l y connect ed t o v b , wh ile th e i nvert i ng i nput and t h e out put are pi nned out . unl i k e m o st op-am ps, t h e am pl i f i e r has an al l - npn out put st age, whi c h m a xi m i zes phase m a rgi n and gai n -bandwi d t h . th is featu r e en su res stab ility at g a in s less th an u n ity, as well as with a wide range of reactive loads. the open l oop gai n i s t y pi cal l y 80 db (f<100 hz), and t h e gai n - bandwi d t h i s t y pi cal l y 1.0 m h z. the m a xi m u m p-p out put swi ng i s t y pi cal l y 1.0 vol t l e ss t h an v cc with an out put i m pedance of <10 ? u n til cu rren t lim itin g is reached (typically 1.5 m a ). i nput bias current at mci is t y pi cal l y 40 na out of t h e pi n. figure 5. microphone amplifier and mute th e m u tin g fu n c tio n (pin 1 2 ) , wh en activ ated , will red u ce th e g a in o f th e am p lifier to = -3 9 d b (will rmi = 5.1 k ? ) by short i ng t h e out put t o t h e i nvert i ng i nput (see fi gure 5). the m u t e i nput has a t h reshol d of 1.5 vol t , and t h e vol t a ge at t h i s pi n m u st be kept wi t h i n t h e range of ground and v cc . if t h e m u t e funct i on i s not used, t h e pi n shoul d be grounded. hybrid amplifiers th e two h y b r id am p lifiers (at hto+, hto-, an d hti), in co n j u n c tio n with an ex tern al tran sfo r m e r, provi de t h e t w o-t o -four wi re convert er for i n t e rfaci ng t o t h e t e l e phone l i n e. the gai n of t h e fi rst am pl i f i e r (hti t o hto-) is set by external resistors (gain = -r hf /r hi in fi gure 8), and i t s out put dri v es t h e second am pl i f i e r, t h e g a in o f wh ich is in tern ally set at -1 .0 . un lik e m o st o p - am ps, t h e am pl i f i e rs have an al l - npn out put st age, whi c h m a xi m i zes phase m a rgi n and gai n -bandwi d t h . th is featu r e en su res stab ility at g a in s less th an u n ity, as well as with a wide range of reactive loads. the open l oop gai n of t h e fi rst am pl i f i e r i s t y pi cal l y 80 db , and t h e gain bandwidth of each am plifier is 1.0 m h z. the m a xim u m p-p output swing of each am plifier is typically 1 . 2 v o lts less th an v cc wi t h an out put i m pedance of <10 ? until current lim iting is reached (typically 8 . 0 m a ). th e o u t p u t cu rren t cap ab ility is g u a ran t eed to be a m i ni m u m of 5.0 m a . the bi as current at hti i s t y pi cal l y 30 na out of t h e pi n. the connect i ons t o t h e coupl i ng t r ansform e r are shown i n t h e expanded logi c di agram (fi gure 8). the bl ock l a bel e d zbal i s t h e bal a nci ng net w ork necessary t o m a tch th e lin e im p e d a n ce. filter th e o p e ratio n o f th e filter circu it is d e term in ed b y t h e ext e rnal com ponent s. the ci rcui t wi t h i n t h e KK34118, from pi ns fi t o fo i s a buffer wi t h a hi gh i nput i m pedance (>1.0 m ? ), and a l o w out put i m pedance (<50 ? ). the confi gurat i on of t h e ext e rnal com ponent s d e term in es wh eth e r th e circu it is a h i g h - p a ss filter (as sh o w n in fig u r e 8 ) , a lo w-p a ss filter, o r a b a n d - p a ss filter. fi gure 6. hi gh pass fi l t er as a high pass filter, with the com ponents shown in figure 6 the filter will keep out 60 hz (and 120 hz) hum whi c h can be pi cked up by t h e ext e rnal t e l e phone l i n es. 6 KK34118
as a lo w p a ss filter (fig u r e 7 ) , it can b e u s ed to ro ll off the high and frequencies in the receive circuit, which ai ds prot ect i ng agai nst acoust i c feedback probl em s. w i t h an appropri a t e choi ce of an i nput coupl i ng capaci t o r t o th e lo w p a ss filter, a b a n d p a ss filter is fo rm ed . the out put vol t a ge at v b (pin 1 5 ) is (v cc - 0.7)/ 2 , and provi des t h e ac ground for t h e sy st em . the out put i m pedance at v b is 400 ? , and i n conjunct i on wi t h t h e external capacitor at v b , fo rm s a lo w p a ss filter fo r power suppl y reject i on. figure 7. low pass filter since v b bi ases t h e m i crophone and hy bri d am pl i f i e rs, t h e am ount of suppl y reject i on at t h ei r o u t p u t s is d i rectly related to th e rej ectio n at v b , as well as their respective gains. the c h i p di sabl e (pi n 3) perm i t s poweri ng down t h e ic t o conserve power and/ or for m u t i ng purposes. w i t h cd 0.8 vol t s , norm a l operat i on i s i n effect . w i t h cd 2.0 vol t s and v cc , t h e ic i s powered down. in t h e powered down m ode, t h e m i crophone and t h e hy bri d am pl i f i e rs are di sabl ed, and t h ei r out put s go t o a hi gh i m pedance st at e. addi t i onal l y , t h e bi as i s rem oved from th e filter (pin s 1 , 2 ) , th e atten u a to rs (pin s 8 , 9 , 2 1 , 2 2 ) , or from pi ns 13, 14, and 15 (t he at t e nuat o rs are di sabl ed, however, and will not pass a signal). the input i m pedance at c d i s t y pi cal l y 90 k ? , has a t h reshol d of 1.5 vol t s , and t h e vol t a ge at t h i s pi n m u st be kept wi t h i n t h e range of ground and v cc . if c d i s not used, t h e pi n shoul d be grounded. power supply, v b , and chip disable the power suppl y vol t a ge at v cc (pin 4 ) is to b e bet w een 3.5 and 6.5 vol t s for norm a l operat i on, wi t h reduced operat i on possi bl e down t o 2.8 vol t s . pin description pin no designation description 1 f o filter o u t p u t . ou tp u t im p e d a n ce is less th an 5 0 ? . 2 f i filter input. input im pedance is greater than 1.0 m ? . 3 c d c h i p di sabl e. a l ogi c l o w (<0.8 v) set s norm a l operat i on. a l ogi c hi gh (>2.0 v) di sabl es t h e ic t o conserve power. input i m pedance i s nom i n al l y 90 k ? . 4 v cc a suppl y vol t a ge of +2.8 t o +6.5 vol t s i s requi red, at 5.0 m a . as v cc falls from 3.5 to 2.8 volts, an agc circuit redu ces the receive attenuator gain by 25 db (when in the receive m ode). 5 hto+ out put of t h e second hy bri d am pl i f i e r. th e gai n i s i n t e rnal l y set at -1.0 t o provi de a di fferent i a l out put , i n conjunct i on wi t h hto-, t o t h e hy bri d t r ansform e r. 6 hto- ou tp u t o f th e first h y b r id am p lifier. th e g a in o f th e am p is set b y ex tern al resisto r s. 7 h t i input and sum m i ng node for t h e fi rst hy bri d am pl i f i e r. dc l e vel i s v b. 8 txo ou tp u t o f th e tran sm it atten u a to r. dc lev e l is ap p r o x i m a tely v b . 9 txi input t o t h e t r ansm i t at t e nuat o r. m a x. si gnal l e vel i s 350 m v rm s. input i m pedance is 10 k ? . 10 m c o out put of t h e m i crophone am pl i f i e r. the gai n of t h e am pl i f i e r i s set by ext e rnal resistors. 1 1 m c i input and sum m i ng node of t h e m i crophone am pl i f i e r. dc l e vel i s v b . (cont i nued) 7 KK34118
pin description pin no designation description 12 m u t m u t e i nput . a l ogi c l o w (<0.8 v) set s norm a l operat i on. a l ogi c hi gh (>2.0 v) m u t e s t h e m i crophone am pl i f i e r wi t hout affect i ng t h e rest of t h e ci rcui t . input i m pedance i s nom i n al l y 90 ? . 13 vlc vol u m e cont rol i nput . w h en vlc = v b , the receive attenuator is at m a xim u m gain when in the receive m ode. w h en vlc = 0.3 v b , the receive gain is down 35 db. does not affect the transm it m ode. 1 4 c t an r c t h i s pi n set s t h e response t i m e for t h e ci rcui t t o swi t c h m odes. 1 5 v b an out put vol t a ge v cc / 2 . thi s vol t a ge i s a sy st em ac ground, and bi ases t h e v o l u m e co n t ro l. a filter cap is req u i red . 16 c p t an r c at t h i s pi n set s t h e t i m e const a nt for t h e t r ansm i t background m oni t o r. 17 tli2 input t o t h e t r ansm i t l e vel det ect or on t h e m i ke speaker si de. 18 tlo2 out put of t h e t r ansm i t l e vel det ect or on t h e m i ke/ s peaker si de, and i nput t o t h e t r ansm i t background m oni t o r. 19 rlo2 output of the receive level detector on the m i ke/speaker side. 20 rli2 input to the receive level detector on the m i ke/speaker side. 21 rxi input to the receive attenuator and dial tone detector. max input level is 350 m v r m s. input i m pedance i s 10 k ? . 22 rxo output of the receive attenua tor. dc level is approxim a tely v b . 23 tli1 input t o t h e t r ansm i t l e vel det ect or on t h e l i n e si de. 24 tlo1 out put of t h e t r ansm i t l e vel det ect or on t h e l i n e si de. 25 r l o 1 output of the receive level detector on the line side, and input to the receive background m oni t o r. 26 rli1 input the receive leve l detector on the line side. 27 cpr an rc at this pin sets the tim e c onstant for the receive background m onitor. 28 gnd ground pi n for t h e ent i r e ic. maximum ratings * s y m b o l p a r a m e t e r v a l u e u n i t v cc suppl y vol t a ge (pi n 14) -1.0 t o +7.0 v v in input vol t a ge at c d (pi n 3), m u t (pi n 12) -1.0 t o v cc +1.0 v v v in input vol t a ge at vlc (pi n 13) -1.0 t o v cc +0.5 v v v in input vol t a ge at txi(pi n 9), r x i (pi n 21), fi (pi n 2) -0.5 t o v cc +0.5 v v tst g st orage tem p erat ure r a nge -65 t o +150 c * m a xi m u m r a t i ngs are t hose val u es bey ond whi c h dam a ge t o t h e devi ce m a y occur. functional operation should be restricted to the reco m m e nded operating conditions. 8 KK34118
recommended operating conditions s y m b o l p a r a m e t e r m i n m a x u n i t v cc suppl y vol t a ge (pi n 4) 3.5 6.5 v v in input vol t a ge at c d (pi n 3), m u t (pi n12) 0 v cc v i vb v b c u rrent (pi n 15) 500 a v in input vol t a ge at vlc (pi n 13) 0.3 x v b v b v v in at t e nuat o r input si gnal vol t a ge (pi n s 9, 21) 0 350 m v rm s g m i crophone am pl i f i e r, hy bri d am pl i f i e r gai n 0 40 db i l load c u rrent r xo, txo pi ns 8,22) m c o (pi n 10) hto-, hto+ (pins 6,5) 0 0 0 2.0 1.0 5.0 ma t a operat i ng tem p erat ure -25 +70 c thi s devi ce cont ai ns prot ect i on ci rcui t r y t o guard agai ns t dam a ge due t o hi gh st at i c vol t a ges or el ect ri c fi el ds. however, precautions m u st be taken to avoid applications of any voltage highe r than m a xim u m rated voltages to this hi gh-i m pedance ci rcui t . for proper operat i on, v in and v out shoul d be const r ai ned t o t h e range gnd (v in or v out ) v cc . unused i nput s m u st al way s be t i e d t o an appropri a t e l ogi c vol t a ge l e vel (e.g., ei t h er gnd or v cc ). unused out put s m u st be l e ft open. electrical characteristics (t a = -25 to +70 c, v cc = 5.0 v , c d = 0.8 v, unl ess not ed) symbol parameter test conditions guaranteed limits unit m i n m a x power supply i cc v cc suppl y c u rrent v cc =6.5 v, cd =0.8 v v cc =6.5 v, cd =2.0 v - - 10 1.0 ma r cd c d input r e si st ance v cc = v cd = 6.5 v 37.5 - kk ? v cdh c d input hi gh vol t a ge v cc = v cd = 6.5 v 2.0 v cc v v cdl c d input low vol t a ge v cc = v cd = 6.5 v 0 0.8 v v b v b out put vol t a ge 1.35 3.0 v attenuator (vlc = v b , unl ess not ed) g rx g rx ? g rx1 * ? g rx2 * g rx1 ? g rx3 * receive attenuator gain ( f =1.0 khz) r x m ode, r x i=150 m v rm s, (v cc =5.0 v) r x m ode, r x i=150 m v rm s (v cc =3.5 v) gai n c h ange -v cc =3.5 v versus v cc =5.0 v agc gain change - v cc =2.8 v versus v cc =5.0 v idl e m ode, r x i=150m vrm s r a nge (r x t o tx m ode) 1.5 1.5 -0.5 - -25 49 10.0 10.0 +0.5 -15 -15 54 db v cr * vol u m e c ont rol r a nge r x m ode, 0.3v b KK34118
electrical characteristics (t a = -25 to +70 c, v cc = 5.0 v , c d = 0.8 v, unl ess not ed) symbol parameter test conditions guaranteed limits unit m i n m a x ? v rxo ? rxo dc voltage rx to tx mode - 190 mv v rxoh rxo high voltage i out = -1.0 m a ,rxi=v b +1.5v, v ct =2.6 v 2 . 8 - v v rxol rxo low voltage i out = +1.0 m a ,rxi=v b -1.0v, v ct =2.6 v output m easured with respect to v b - v b - 0 . 7 5 v r rxi r x i input r e si st ance r x i=350 m v rm s, f = 1.0 khz 5.25 17.5 k ? g tx g txi ? g txi * tran sm it atten u a to r gain ( f =1.0 khz) tx m ode, txi=150 m v rm s idl e m ode, r x i=-150 m v rm s r a nge (tx t o r x m ode) 1.5 -25 49 10.0 -15 54 db ? v txo ? txo dc voltage tx to rx mode - 190 mv v txoh txo high voltage i out = -1.0 m a ,txi=v b +1.5v, v ct =1.6 v 2 . 8 - v v txol txo low voltage i out = +1.0 m a ,txi=v b -1.0v, v ct =1.6 v output m easured with respect to v b - v b - 0 . 7 5 v r txi txi input r e si st ance txi=350 m v rm s, f = 1.0 khz 5.25 17.5 k ? attenuator control i ctr c t source c u rrent (swi t c hi ng t o r x m ode) f = 1 khz, v lc = v b =c t - 1 0 6 - 3 0 a i ctt c t si nk c u rrent (swi t c hi ng t o tx m ode) f = 1 khz, v lc = v b =c t + 3 0 + 1 0 6 a r fi * c t fast idle internal resistance 1 . 5 3 . 6 k ? v dt * di al tone det ect or threshol d 10 20 m v microphone amlifier (v mut 0.8 v, a+ = 31 db , unl ess ot herwi s e not ed) mco vos out put offset v mco - v b , feedback r = 180 k ? - 6 2 + 6 2 m v a volm open loop gai n f = 100 hz 60 - db v mcoh out put hi gh vol t a ge i out =-1.0 m a ,v mci =v b +1.5 v 2.8 - v v mcol output low voltage i out =1.0 m a , v mci =v b - 1.0 v - 250 m v gm t m u t i ng ( ? gain) f = 1.0 khz,v mci = 150 m v 0.8 v v mut 2.0 v 5 2 - db r mut m u t input r e si st ance v cc = v mut = 6.5 v 37.5 - k ? v muth m u t input -hi gh 2.0 v cc v v mutl m u t input -low 0 0.8 v (cont i nued) 10 KK34118
electrical characteristics (t a = -25 to +70 c, v cc = 5.0 v , c d = 0.8 v, unl ess not ed) symbol parameter test conditions guaranteed limits unit m i n m a x hybrid amplifiers h vos hto - offset v hto- - v b , feedback r= 51 k ? v b - 25 v b + 2 5 m v hb vos hto - to hto+ offset feedback r= 51 k ? v b - 37 v b + 3 7 m v a volh open loop gai n hti t o hto-, f = 100 hz, v hti = 20 m v 5 7 - db a vclh c l osed loop gai n hto- t o hto+ -2.8 2.2 db v ht-h hto- high voltage i out =-5.0 m a , v hti =v b -1.0 v 2.8 - v v ht-l hto- low voltage i out =5.0 m a , v hti =v b +1.5 v - 375 m v v ht+h hto+ high voltage i out =-5.0 m a ,v hti =v b +1.5 v 2.8 - v v ht+l hto+ low voltage i out =5.0 m a , v hti =v b -1.0 v - 562 m v level detectors and background noise monitors i th * transm it-receive switching threshol d ratio o f cu rren t at rli1 + rli2 t o 20 a at tli1 + tli2 to switch fro m tx to rx 0 . 8 1 . 2 filter fo vos voltage offset at fo v fo -v b , 220 k ? from v b to fi v b - 250 v b + 2 5 m v i fo fo si nk c u rrent v b = v fo , v fi = 0 v 112 500 a note. 1. all currents into a device pin are positive, those out of a pin are negative. alge braic convention rather than m a g n itu d e is u s ed to d e fin e lim its. * @25 c 11 KK34118
figure 8. expanded logic diagram 12 KK34118
figure 9. kk 34118 application circuit (basic line powered speakerphone) 1. 0 k 0. 2 0. 1 0. 1 5. 1 k 10 9 8 10 k 5. 1 k 5. 1 k tx o tl i 1 0. 1 0. 1 82 0 300 0. 05 ht i ht o - ht o+ r r 5 0. 01 ho o k sw it c h ti p ri n g di s - abl e 100 0 f (n ot e 3) 1n 4733 5. 1 v 4 3 24 27 25 28 fi 1 fo rl i1 26 13 dt d ag c 20 2 2 21 vl c vo l u m e co n t r o l 1) t hes e t w o res i s t o r s depen d on t he s p e c i f i c m i c r oph one s e l e c t ed. 2) c o m pon e n t v a l u e s s how n ar e r e c o m m endat i ons onl y , a nd w i l l v a r y i n di f f e rent appl i c at i ons . 3) t h i s c a p a c i t o r m u s t be phy s i c a l l y adj a c ent t o p i n 4 of t he kk 34118. 4) b n m - b a c k ground n o i s e m oni t o r; d t d = d i al t one d e t e c t or . 5) r e c o m m e nded t r a n s f orm e r: s t anc or t t p c -13, m i c r ot ran t 5115 . 6) c a p a c i t o r v a l ues ar e i n f unl es s ot he rw i s e not ed. rl i 2 220 f 5. 0 f 47 f 120 k rl o 2 19 16 cp t 18 mu t tl o 2 12 mu t e 2. 0 f 100 k 2. 0 f 14 15 rx o rx i + 1 220 k 56 k 9. 1 k 5. 1 k 200 p f 1 10 k 10 k 0. 05 0. 1 4 3 1 6 7 kk 34119 kk 34118 8 5 25 s peak er (3 00 m w ) ? r r 20 k 10 k 0. 05 0. 1 cd tl o 1 2. 0 f 2. 0 f 100 k 47 f 470 0pf 470 0pf cp r rl o1 gn d 2 f ilt e r 23 7 6 tx i a t t enu at or a t t enu at or a t t enu at or co n t r o l bn m bn m 17 tl i 2 11 + + + + + + + + + + - - - - - - - - - - 5. 1 k 0. 02 180 k (n ot e1) mi k e 620 20 f v cc v b v b v b r hi v b v b v b v b v b v b v b v b v cc v cc c t v b v cc v cc v cc v b 220 f r mi r mf r hf 51k 220pf 13 KK34118
n s u f f i x p l as t i c d i p (m s - 0 0 1 a b ) sy m b o l m i n m a x a 3 5. 1 3 9. 7 b 1 2. 32 1 4 . 7 3 c6 d 0 .3 6 0 .5 6 f 0 .7 7 1 .7 8 g h j0 10 k 2 .9 2 5 .0 8 no t e s : l 1 5. 24 1 5 . 8 7 1. d i m e n s i o n s ?a ?, ?b ? d o n o t i n cl u d e m o l d f l as h o r p r o t r u s i o n s . m 0 . 2 0. 38 m a x i m u m m o l d f l a s h o r p r o t r u s i o n s 0. 25 m m ( 0 . 010) p e r s i d e . n0 . 3 8 d su f f i x so i c (m s - 0 5 9 a d) sy m b o l m i n m a x a 1 7. 7 1 8. 5 b 8 .2 3 8 .9 c 2 .3 5 3 .0 5 d 0 .3 5 0 .5 f 0 . 4 1. 27 g h no t e s : j0 8 1. d i m e ns i o ns a a n d b d o no t i n c l ud e m o l d f l a s h o r p r ot r u s i o n . k 0 .0 5 0 .3 5 2. m a x i m u m m o l d f l a s h o r p r o t r u s i o n 0. 15 m m ( 0 . 006) p e r s i d e m 0 .1 4 0 .3 2 fo r a ; fo r b ? 0. 25 m m ( 0 . 010) p e r s i d e . p 1 1. 5 1 2. 7 r 0 .2 5 0 .7 5 11 . 4 3 d i me n s i o n , mm d i me n s i o n , mm 2. 54 15 . 2 4 1. 27 . 3 5 a b c k c m j f m p h g d r x 45 se a t i n g pl a n e 0.2 5 (0. 0 10) m t -t - 1 28 14 15 l h m j a b f g d se a t i n g pl a n e n k 0.2 5 ( 0 . 010) m t -t - c 1 28 14 15 14 KK34118

▲Up To Search▲

Price & Availability of KK34118

	To Download KK34118 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .