technical data kk74ls244 octal 3-state noninverting buffer/line driver/line receiver ordering information kk 74ls244n plastic kk 74ls244dw soic t a = 0 to 7 0 c for all packages these oct a l buffers and l i n e dri v ers and desi gned speci fi cal l y t o i m prove bot h t h e perform ance and densi t y of t h ree-st at e m e m o ry address drivers, clock drivers, and busor iented receivers and transm itters. thi s devi se feat ures hi gh fan-out , i m proved fan-i n , and 400 m v noi se ma r g i n . it can be used t o dri v e t e rm i n at ed l i n es down t o 133 ohm s. ? 3-st at e out put s dri v e b u s li nes or b u ffer m e m o ry address r e gi st ers ? p-n-p input s r e duce d-c loadi ng ? hy st eresi s at input s im proves noi s e m a rgi n s pin assignment logic diagram pin 20=v cc pin 10 = gnd function table input s o u t put s enable a, enable b a , b y a , y b l l l l h h h x z x=don?t care z = hi gh i m pedance 1
kk74ls244 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 -15 m a i ol low level out put c u rrent 24 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 = -1.0 m a 2.7 v v cc = m i n, i oh = -3.0 m a 2.4 v cc = m i n, i oh = -15 m a 2.0 v ol low level out put vol t a ge v cc = m i n, i ol = 12 m a 0.4 v v cc = m i n, i ol = 24 m a 0.5 v t+ - v t- h y s t e r e s i s v cc = m i n 0.2 v i ozh output off current high v cc = m a x, v out = 2.7 v 20 a i ozl output off current low v cc = m a x, v out = 0.4 v -20 a i ih hi gh level input c u rrent v cc = m a x, v in = 2.7 v 20 a v cc = m a x, v in = 7.0 v 0.1 m a i il low level input c u rrent v cc = m a x, v in = 0.4 v -0.2 m a i o out put short c i rcui t c u rrent v cc = m a x, v o =0 v (not e 1) - 4 0 - 2 2 5 m a i cc suppl y o u t put s hi g h v cc = m a x 27 m a c u rrent out put s low out put s open 46 al l out put s di sabl ed 5 4 note 1: not m o re than one out put should be shorted at a tim e, and durati on of the short-circuit should not exceed one second 2
kk74ls244 ac electrical characteristics (t a = 25 c, v cc = 5.0 v, t r = 15 ns, t f = 6.0 ns) 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 m i n m a x u n i t t plh propagat i on del a y , dat a t o out put 1 8 n s t phl propagat i on del a y , dat a t o out put c l = 45 pf, r l = 667 ? 1 8 n s t pzh out put enabl e ti m e 23 ns t pzl out put enabl e ti m e 30 ns t phz out put di sabl e ti m e c l = 5 pf 18 ns t plz out put di sabl e ti m e r l = 667 ? 2 5 n s t pzl - s1 cl osed, s2 opened t pzh - s1 opened, s2 cl osed t plz , t phz - s1 and s2 cl osed fi gure 1. sw i t chi n g waveforms (see figure 3) fi gure 2. sw i t chi n g waveforms (see figure 4) 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. 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 figure 4. test circuit 3
kk74ls244 expanded logic diagram 4
kk74ls244 n s u f f i x p l as t i c d i p (m s - 0 0 1 a d) sy m b o l m i n m a x a 24. 8 9 26. 92 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 3 a c) sy m b o l m i n m a x a 12. 6 1 3 b 7. 4 7 . 6 c 2. 35 2. 65 d 0. 33 0. 51 f 0. 4 1 . 2 7 g h no t e s : j 0 8 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 pr o t r u s i on . k 0. 1 0 . 3 2. m a x i m u m m o l d fl a s h o r p r o t ru s i o n 0 . 1 5 m m (0 . 0 0 6 ) p e r s i d e m 0. 23 0. 32 f o r a ; fo r b ? 0. 25 m m ( 0 . 010) p e r s i d e . p 10 10. 65 r 0. 25 0. 75 d i me n s i o n , mm 1. 27 9. 53 d i me n s i o n , mm 2. 54 7. 62 a b h c k c m j f m p g d r x 4 5 se a t i n g pl a n e 0.2 5 ( 0 . 0 1 0 ) m t -t - 1 20 10 11 l h m j a b f g d se a t i n g pl an e n k 0.2 5 ( 0 . 010) m t -t - c 1 20 10 11 5
|
