technical data kk74ac257 quad 2-input data selector/multiplexer with 3-state outputs high-speed silicon-gate cmos ordering information kk 74ac257n plastic kk 74ac257d soic t a = -40 to 8 5 c for all packages the kk 74ac257 is identical in pinout to the ls/als257, hc / h c t 257. the devi ce i nput s are com p at i b l e wi t h st andard c m os out put s; wi t h pul l up resi st ors, t h ey are com p at i b l e wi t h ls/ a ls out put s. thi s devi ce sel ect s a (4-bi t ) ni bbl e from ei t h er t h e a or b i nput s as det e rm i n ed by t h e sel ect i nput . the ni bbl e i s present e d at t h e out put s i n noni nvert ed from when t h e out put enabl e pi n i s at a l o w l e vel . a hi gh l e vel on t h e out put enabl e pi n swi t c hes t h e out put s i n t o t h e hi gh- im pedance state. ? outputs directly interf ace to cmos, nmos, and ttl ? operat i ng vol t a ge r a nge: 2.0 t o 6.0 v ? low input c u rrent : 1.0 a; 0.1 a @ 25 c ? high noise im m unity characteristic of cmos devices ? out put source/ si nk 24 m a pin assignment logic diagram pin 16 =v cc pin 8 = gnd function table input s o u t put s out put enable s e l e c t y 0 - y 3 h x z l l a 0 - a 3 l h b 0 - b 3 x=don?t care z = hi gh-i m pedance st at e a0 -a3 , b0 -b3 = th e lev e ls o f th e resp ectiv e ni bbl e input s 1
kk74ac257 maximum ratings * sym b o l p a r a m e t e r valu e un i t v cc dc suppl y vol t a ge (referenced t o gnd) -0.5 t o +7.0 v v in dc input vol t a ge (referenced t o gnd) -0.5 t o v cc +0.5 v v out dc output voltage (referenced to gnd) -0.5 to v cc +0.5 v i in dc input c u rrent , per pi n 20 ma i out dc out put si nk/ source c u rrent , per pi n 50 ma i cc dc suppl y c u rrent , v cc and gnd pins 50 ma p d po wer dissip a tio n in still air, plastic dip+ soic package+ 750 500 mw tst g st orage tem p erat ure -65 t o +150 c t l lead tem p erat ure, 1 m m from c a se for 10 seconds (plastic dip or soic package) 260 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. +derat i ng - pl ast i c dip: - 10 m w / c from 65 t o 125 c soic package: : - 7 m w / c from 65 t o 125 c recommended operating conditions sy m bol p a r a m e t e r m i n m a x uni t v cc dc suppl y vol t a ge (referenced t o gnd) 2.0 6.0 v v in , v out dc input vol t a ge, out put vol t a ge (referenced t o gnd) 0 v cc v t j junct i on tem p erat ure (pdip) 140 c t a operating tem p erature, all package types -40 +85 c i oh out put c u rrent - hi gh -24 m a i ol out put c u rrent - low 24 m a t r , t f input r i se and fal l ti m e * (except schm itt inputs) v cc =3.0 v v cc =4.5 v v cc =5.5 v 0 0 0 150 40 25 ns/ v * v in from 30% t o 70% v cc 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. 2
kk74ac257 dc electrical characteristics (voltages referenced to gnd) v cc guaranteed lim its sy m bol p a r a m e t e r test c ondi t i o n s v 25 c - 4 0 c to 85 c un it v ih m i ni m u m hi gh- level input vol t a ge v out =0.1 v or v cc -0.1 v 3.0 4.5 5.5 2.1 3.15 3.85 2.1 3.15 3.85 v v il m a x i mu m l o w - level input vol t a ge v out =0.1 v or v cc -0.1 v 3.0 4.5 5.5 0.9 1.35 1.65 0.9 1.35 1.65 v v oh m i ni m u m hi gh- level out put vol t a ge i out -50 a 3.0 4.5 5.5 2.9 4.4 5.4 2.9 4.4 5.4 v * v in = v ih or v il i oh =-12 m a i oh =-24 m a i oh =-24 m a 3.0 4.5 5.5 2.56 3.86 4.86 2.46 3.76 4.76 v ol m a x i mu m l o w - level out put vol t a ge i out 50 a 3.0 4.5 5.5 0.1 0.1 0.1 0.1 0.1 0.1 v * v in =v ih or v il i ol =12 m a i ol =24 m a i ol =24 m a 3.0 4.5 5.5 0.36 0.36 0.36 0.44 0.44 0.44 i in m a xi m u m input leakage current v in =v cc or gnd 5.5 0.1 1.0 a i oz m a x i mu m t h r e e - state leakage current v in (oe)= v ih or v il v in =v cc or gnd v out =v cc or gnd 5.5 0.5 5.0 a i old +min im u m dyn a m i c out put c u rrent v old =1.65 v m a x 5.5 75 m a i ohd +min im u m dyn a m i c out put c u rrent v ohd =3.85 v m i n 5.5 -75 m a i cc m a x i mu m q u i e s c e n t suppl y c u rrent (per package) v in =v cc or gnd 5.5 8 .0 80 a * al l out put s l o aded; t h reshol ds on i nput associ at ed wi t h out put under t e st . +m axi m um t e st durat i on 2.0 m s , one out put l o aded at a t i m e. no te: i in and i cc @ 3 . 0 v are g u a ran t eed to b e less th an o r eq u a l to th e resp ectiv e lim it @ 5 . 5 v v cc 3
kk74ac257 ac electrical characteristics (c l =50pf, input t r =t f =3.0 ns) v cc * guaranteed lim its sym b o l p a r a m e t e r v 25 c - 4 0 c to 85 c unit min max m in max t plh propagat i on del a y , ni bbl e a or b t o out put y (fi gure 1) 3.3 5.0 1.5 1.5 8.5 6.0 1.0 1.0 9.0 7.0 ns t phl propagat i on del a y , ni bbl e a or b t o out put y (fi gure 1) 3.3 5.0 1.5 1.5 8.5 6.0 1.0 1.0 9.0 7.0 ns t plh propagat i on del a y , sel ect t o out put y (fi gure 2) 3.3 5.0 1.5 1.5 10.5 7.5 1.5 1.0 11.5 8.5 ns t phl propagat i on del a y , sel ect t o out put y (fi gure 2) 3.3 5.0 1.5 1.5 10.5 7.5 1.5 1.0 11.5 8.5 ns t pzh propagat i on del a y , out put enabl e t o out put y (fi gure 3) 3.3 5.0 1.5 1.5 9.5 7.5 1.0 1.0 10.5 8.5 ns t pzl propagat i on del a y , out put enabl e t o out put y (fi gure 3) 3.3 5.0 1.5 1.5 9.0 8.5 1.0 1.0 10.0 9.5 ns t phz propagat i on del a y , out put enabl e t o out put y (fi gure 3) 3.3 5.0 1.5 1.5 10.0 9.0 1.0 1.0 11.0 10.0 ns t plz propagat i on del a y , out put enabl e t o out put y (fi gure 3) 3.3 5.0 1.5 1.5 9.0 8.0 1.0 1.0 10.0 9.0 ns c in m a xi m u m input c a paci t a nce 5.0 4 .5 4.5 pf typical @25 c,v cc =5.0 v c pd power di ssi pat i on c a paci t a nce 50 pf * vol t a ge r a nge 3.3 v i s 3.3 v 0.3 v vol t a ge r a nge 5.0 v i s 5.0 v 0.5 v fi gure 1. sw i t chi n g waveforms fi gure 2. sw i t chi n g waveforms 4
kk74ac257 fi gure 3. sw i t chi n g waveforms expanded logic diagram 5
kk74ac257 n s u f f i x p l as t i c di p (m s - 0 0 1 b b ) sy m b o l m i n m a x a 18. 67 19. 69 b 6. 1 7 . 1 1 c 5. 33 d 0. 36 0. 56 f 1. 14 1. 78 g h j 0 10 k 2. 92 3. 81 no t e s : l 7. 62 8. 26 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 . 3 6 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 . n 0. 38 d su f f i x so i c (m s - 0 1 2 a c) sy m b o l m i n m a x a 9. 8 1 0 b 3. 8 4 c 1. 35 1. 75 d 0. 33 0. 51 f 0. 4 1 . 2 7 g h j 0 8 no t e s : k 0. 1 0 . 2 5 1. d i m e n s 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 on . m 0. 19 0. 25 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 p 5. 8 6 . 2 fo r a ; fo r b ? 0. 25 m m ( 0 . 010) p e r s i d e . r 0. 25 0. 5 5. 72 2. 54 7. 62 1. 27 d i me n s i o n , mm d i me n s i o n , mm a b h c k c m j f m p g d r x 4 5 se a t i n g pl an e 0 . 25 ( 0 . 010 ) m t -t - 1 16 8 9 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 16 8 9 6
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