technical data IN74LS244 octal 3-state noninverting buffer/line driver/line receiver ordering information IN74LS244n plastic IN74LS244dw soic t a = 0 to 70 c for all packages these octal buffers and line drivers and designed specifically to improve both the performance and density of three-state memory address drivers, clock drivers, and busor iented receivers and transmitters. this devise features high fan-out, improved fan-in, and 400 mv noise margin. it can be used to drive terminated lines down to 133 ohms. ? 3-state outputs drive bus lines or buffer memory address registers ? p-n-p inputs reduce d-c loading ? hysteresis at inputs improves noise margins pin assignment logic diagram pin 20=v cc pin 10 = gnd function table inputs outputs enable a, enable b a,b ya,yb l l l l h h h x z x=don?t care z = high impedance rev. 00
IN74LS244 rev. 00 maximum ratings * symbol parameter value unit v cc supply voltage 7.0 v v in input voltage 7.0 v v out output voltage 5.5 v tstg storage temperature range -65 to +150 c * maximum ratings are those values beyond which damage to the device may occur. functional operation should be restricted to the reco mmended operating conditions. recommended operating conditions symbol parameter min max unit v cc supply voltage 4.75 5.25 v v ih high level input voltage 2.0 v v il low level input voltage 0.8 v i oh high level output current -15 ma i ol low level output current 24 ma t a ambient temperature range 0 +70 c dc electrical characteristics over full operating conditions guaranteed limit symbol parameter test conditions min max unit v ik input clamp voltage v cc = min, i in = -18 ma -1.5 v v oh high level output voltage v cc = min, i oh = -1.0 ma 2.7 v v cc = min, i oh = -3.0 ma 2.4 v cc = min, i oh = -15 ma 2.0 v ol low level output voltage v cc = min, i ol = 12 ma 0.4 v v cc = min, i ol = 24 ma 0.5 v t+ - v t- hysteresis v cc = min 0.2 v i ozh output off current high v cc = max, v out = 2.7 v 20 a i ozl output off current low v cc = max, v out = 0.4 v -20 a i ih high level input current v cc = max, v in = 2.7 v 20 a v cc = max, v in = 7.0 v 0.1 ma i il low level input current v cc = max, v in = 0.4 v -0.2 ma i o output short circuit current v cc = max, v o =0 v (note 1) -40 -225 ma i cc supply outputs high v cc = max 27 ma current outputs low outputs open 46 all outputs disabled 54 note 1: not more than one out put should be shorted at a time, and durati on of the short-circuit should not exceed one second
IN74LS244 ac electrical characteristics (t a = 25 c, v cc = 5.0 v, t r = 15 ns, t f = 6.0 ns) symbol parameter test condition min max unit t plh propagation delay, data to output 18 ns t phl propagation delay, data to output c l = 45 pf, r l = 667 18 ns t pzh output enable time 23 ns t pzl output enable time 30 ns t phz output disable time c l = 5 pf 18 ns 25 ns t plz output disable time r l = 667 t pzl - s1 closed, s2 opened t pzh - s1 opened, s2 closed t plz , t phz - s1 and s2 closed figure 1. switching waveforms (see figure 3) figure 2. switching waveforms (see figure 4) notes a. c includes probe and jig capacitance. notes a. c includes probe and jig capacitance. l l b. all diodes are 1n916 or 1n3064. b. all diodes are 1n916 or 1n3064. figure 3. test circuit figure 4. test circuit rev. 00
IN74LS244 expanded logic diagram rev. 00
IN74LS244 n suffix plastic dip (ms - 001ad) symbol min max a 24.89 26.92 b 6.1 7.11 c 5.33 d 0.36 0.56 f 1.14 1.78 g h j 0 10 k 2.92 3.81 notes: l 7.62 8.26 1. dimensions ?a?, ?b? do not include mold flash or protrusions. m 0.2 0.36 maximum mold flas h or protrus ions 0.25 mm (0.010) per s ide. n 0.38 d suffix soic (ms - 013ac) symbol min max a 12.6 13 b 7.4 7.6 c 2.35 2.65 d 0.33 0.51 f 0.4 1.27 g h notes: j 0 8 1. dimensions a and b do not include mold flash or protrusion. k 0.1 0.3 2. maximum mold flash or protrusion 0.15 mm (0.006) per side m 0.23 0.32 for a; for b ? 0.25 mm (0.010) per s ide. p 10 10.65 r 0.25 0.75 dimens ion, mm 1.27 9.53 dimens ion, mm 2.54 7.62 a b h c k c m j f m p g d r x 45 seating plane 0.25 (0.010) m t -t- 1 20 10 11 l h m j a b f g d seating plane n k 0.25 (0.010) m t -t- c 1 20 10 11 rev. 00
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