technical data kk74ls157 quad 2-input data selector/multiplexer ordering information kk 74ls157n plastic kk 74ls157d soic t a =0 to 7 0 c for all packages th is m o n o litic d a ta selecto r /m u ltip lex e r co n t ain s in v e rters an d d r iv ers t o suppl y ful l on-chi p dat a sel ect i on t o t h e four out put gat e s. a separat e st robe i nput i s provi ded. a 4-bi t word i s sel ect ed from one of t w o sources and i s rout ed t o t h e four out put s. the ls157 has t h e sam e funct i ons and pi n connect i ons as t h e ls257 but t h e l a t t e r i s provi ded wi t h 3-st at e out put s. ? b u ffered input s and out put s ? c o m m on st robe/ s el ect i nput for al l 4 ci rcui t s 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 l l l a 0 - a 3 l h b 0 - b 3 x=don?t care a0 -a3 , b0 -b3 = th e lev e ls o f th e resp ectiv e dat a -w ord input s 1
kk74ls157 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 7.0 v v in input vol t a ge 7.0 v v out out put vol t a ge 5.5 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. recommended operating conditions s y m b o l p a r a m e t e r m i n m a x unit v cc suppl y vol t a ge 4.75 5.25 v v ih hi gh level input vol t a ge 2.0 v v il low level input vol t a ge 0.8 v i oh hi gh level out put c u rrent -0.4 m a i ol low level out put c u rrent 8.0 m a t a am bi ent tem p erat ure r a nge 0 +70 c dc electrical characteristics over full operating conditions g u a r a n t e e d l i m i t s y m b o l p a r a m e t e r t e s t c o n d i t i o n s m i n m a x unit v ik input c l am p vol t a ge v cc = m i n, i in = -18 m a -1.5 v v oh hi gh level out put vol t a ge v cc = m i n, i oh = -0.4 m a 2.7 v v ol low level out put vol t a ge v cc = m i n, i ol = 4 m a 0.4 v v cc = m i n, i ol = 8 m a 0.5 i ih hi gh level input c u rrent v cc = m a x for pi ns 1,15 40 a v in = 2.7 v a or b i nput 20 v cc = m a x for pi ns 1,15 0.2 m a v in = 7.0 v a or b i nput 0.1 i il low level input c u rrent v cc = m a x for pi ns 1,15 -0.8 m a v in = 0.4 v a or b i nput -0.4 i o out put short c i rcui t c u rrent v cc = m a x, v o = 0 v (not e 1) - 2 0 - 1 0 0 m a i cc suppl y c u rrent v cc = m a x (not e 2) 16 m a note 1: not m o re than one output s hould be shorted at a tim e, and the duration should not exceed one second. note 2: i cc i s m easured wi t h al l out put s open, and 4.5 v appl i e d t o al l i nput s. 2
kk74ls157 ac electrical characteristics (t a =25 c, v cc = 5.0 v, c l = 15 pf, r l = 2 k ? , t r =15 ns, t f = 6.0 ns) 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 t plh propagat i on del a y , input a or b t o out put y 14 ns t phl propagat i on del a y , input a or b t o out put y 14 ns t plh propagat i on del a y , sel ect t o out put y 23 ns t phl propagat i on del a y , sel ect t o out put y 27 ns t plh propagat i on del a y , out put enabl e t o out put y 20 ns t phl propagat i on del a y , out put enabl e t o out put y 21 ns fi gure 1. sw i t chi n g waveforms fi gure 2. sw i t chi n g waveforms notes a. c l i n cl udes probe and ji g capaci t a nce. b . al l di odes are 1n916 or 1n3064. figure 3. test circuit 3
kk74ls157 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 4
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