technical data in74ac157 quad 2-input data selector/multiplexer high-speed silicon-gate cmos ordering information in74ac157n plastic IN74AC157D soic t a = -40 to 85 c for all packages the in74ac157 is identical in pinout to the ls/als157, hc/hct157. the device inputs are compatible with standard cmos outputs; with pullup resistors, they are compatible with ls/als outputs. this device routes 2 nibbles (a or b) to a single port (y) as determined by the select input. the data is presented at the outputs in noninvertered form. a high level on the output enable input sets all four y outputs to a low level. ? outputs directly interf ace to cmos, nmos, and ttl ? operating voltage range: 2.0 to 6.0 v ? low input current: 1.0 a; 0.1 a @ 25 c ? high noise immunity characteristic of cmos devices ? outputs source/sink 24 ma function table inputs outputs output enable select y0-y3 h rev. 00 x l l l a0-a3 l h b0-b3 x=don?t care a0-a3,b0-b3=the levels of the respective data-word inputs logic diagram pin 16 =v cc pin 8 = gnd pin assignment
in74ac157 rev. 00 maximum ratings * symbol parameter value unit v cc dc supply voltage (referenced to gnd) -0.5 to +7.0 v v in dc input voltage (referenced to gnd) -0.5 to 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 current, per pin 20 ma i out dc output sink/source current, per pin 50 ma i cc dc supply current, v cc and gnd pins 50 ma p d power dissipation in still air, plastic dip+ soic package+ 750 500 mw tstg storage temperature -65 to +150 c t l lead temperature, 1 mm from case for 10 seconds (plastic dip or soic package) 260 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. +derating - plastic dip: - 10 mw/ c from 65 to 125 c soic package: : - 7 mw/ c from 65 to 125 c recommended operating conditions symbol parameter min max unit v cc dc supply voltage (referenced to gnd) 2.0 6.0 v v in , v out dc input voltage, output voltage (referenced to gnd) 0 v cc v t j junction temperature (pdip) 140 c t a operating temperature, all package types -40 +85 c i oh output current - high -24 ma i ol output current - low 24 ma t r , t f input rise and fall time * (except schmitt 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% to 70% v cc this device contains protection circuitry to guard agains t damage due to high static voltages or electric fields. however, precautions must be taken to avoid applications of any voltage highe r than maximum rated voltages to this high-impedance circuit. for proper operation, v in and v out should be constrained to the range gnd (v in or v out ) v cc . unused inputs must always be tied to an appropriate logic voltage level (e.g., either gnd or v cc ). unused outputs must be left open.
in74ac157 rev. 00 dc electrical characteristics (voltages referenced to gnd) v cc guaranteed limits symbol parameter test conditions v 25 c -40 c to 85 c unit v ih minimum high- level input voltage 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 maximum low - level input voltage 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 minimum high- level output voltage 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 ma i oh =-24 ma i oh =-24 ma 3.0 4.5 5.5 2.56 3.86 4.86 2.46 3.76 4.76 v ol maximum low- level output voltage 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 ma i ol =24 ma i ol =24 ma 3.0 4.5 5.5 0.36 0.36 0.36 0.44 0.44 0.44 i in maximum input leakage current v in =v cc or gnd 5.5 0.1 1.0 a i old +minimum dynamic output current v old =1.65 v max 5.5 75 ma i ohd +minimum dynamic output current v ohd =3.85 v min 5.5 -75 ma i cc maximum quiescent supply current (per package) v in =v cc or gnd 5.5 8.0 80 a * all outputs loaded; thresholds on input associated with output under test. +maximum test duration 2.0 ms, one output loaded at a time. note: i in and i cc @ 3.0 v are guaranteed to be less than or equal to the respective limit @ 5.5 v v cc
in74ac157 ac electrical characteristics (c l =50pf,input t r =t f =3.0 ns) v cc * guaranteed limits symbol parameter v 25 c -40 c to 85 c unit min max min max t plh propagation delay, input a or b to output y (figure 1) 3.3 5.0 1.5 1.5 8.5 6.5 1.0 1.0 9.0 7.0 ns t phl propagation delay, input a or b to output y (figure 1) 3.3 5.0 1.5 1.5 8.0 6.5 1.0 1.0 9.0 7.0 ns t plh propagation delay, select to output y (figure 2) 3.3 5.0 1.5 1.5 11.5 9.0 1.5 1.5 13.0 10.0 ns t phl propagation delay, select to output y (figure 2) 3.3 5.0 1.5 1.5 11.0 8.5 1.5 1.0 12.0 9.5 ns t plh propagation delay, output enable to output y (figure 3) 3.3 5.0 1.5 1.5 11.5 9.0 1.5 1.5 13.0 10.0 ns t phl propagation delay, output enable to output y (figure 3) 3.3 5.0 1.5 1.5 11.0 9.0 1.5 1.0 12.0 9.5 ns c in maximum input capacitance 5.0 4.5 4.5 pf typical @25 c,v cc =5.0 v c pd power dissipation capacitance 50 pf * voltage range 3.3 v is 3.3 v 0.3 v voltage range 5.0 v is 5.0 v 0.5 v figure 1. switching waveforms figure 2. switching waveforms figure 3. switching waveforms rev. 00
in74ac157 expanded logic diagram a0 b0 a1 b1 a2 b2 a3 b3 oe select y0 y1 y2 y3 rev. 00
in74ac157 n suffix plastic dip (ms - 001bb) symbol min max a 18.67 19.69 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 - 012ac) symbol min max a 9.8 10 b 3.8 4 c 1.35 1.75 d 0.33 0.51 f 0.4 1.27 g h j 0 8 notes: k 0.1 0.25 1. dimensions a and b do not include mold flash or protrusion. m 0.19 0.25 2. maximum mold flas h or protrus ion 0.15 mm (0.006) per s ide p 5.8 6.2 for a; for b ? 0.25 mm (0.010) per s ide. r 0.25 0.5 5.72 2.54 7.62 1.27 dimens ion, mm dimens ion, mm 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 16 8 9 l h m j a b f g d seating plane n k 0.25 (0.010) m t -t- c 1 16 8 9 rev. 00
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