1/10 june 2004 high speed: t pd = 15ns (typ.) at v cc = 6v low power dissipation: i cc = 4 a(max.) at t a =25c high noise immunity: v nih = v nil = 28% v cc (min.) symmetrical output impedance: |i oh | = i ol = 4ma (min) balanced propagation delays: t plh ? t phl wide operating voltage range: v cc (opr) = 2v to 6v pin and function compatible with 54 series 238 device fully compliant with scc-9205-016 description the m54hc238 is an high speed cmos 3 to 8 line decoder fabricated with silicon gate c 2 mos technology. if the device is enabled, 3 binary select inputs (a, b and c) determine which one of outputs will go high. when enable input g1 is held "low" or either g2a or g2b is held "high" decoding function is inhibited and all the 8 outputs go low. three enable inputs are provided to ease cascade connection and application of this address decoder in memory systems. all inputs are equipped with protection circuits against static discharge and transient excess voltage. m54hc238 rad-hard 3 to 8 line decoder pin connection order codes package fm em dilc m54hc238d m54hc238d1 fpc M54HC238K M54HC238K1 dilc-16 fpc-16 rev. 2
m54hc238 2/10 figure 1: iec logic symbols figure 2: input and output equivalent circuit table 1: pin description table 2: truth table x : don?t care pin n symbol name and function 1, 2, 3 a, b, c data inputs 4, 5 g2a g2b enable input (active low) 6 g1 data enable input (active high) 15, 14, 13, 12, 11, 10, 9, 7 y0 to y7 outputs 8 gnd ground (0v) 16 v cc positive supply voltage inputs outputs selected output enable select g2b g2a g1 c b a y0y1y2y3y4y5y6y7 xxlxxxllllllll none xhxxxxllllllll none hxxxxxllllllll none llhlllhlllllll y0 llhllhlhllllll y1 llhlhlllhlllll y2 llhlhhlllhllll y3 llhhllllllhlll y4 llhhlhlllllhll y5 llhhhlllllllhl y6 llhhhhlllllllh y7
m54hc238 3/10 figure 3: logic diagram this logic diagram has not be used to estimate propagation delays table 3: absolute maximum ratings absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditi ons is not implied table 4: recommended operating conditions symbol parameter value unit v cc supply voltage -0.5 to +7 v v i dc input voltage -0.5 to v cc + 0.5 v v o dc output voltage -0.5 to v cc + 0.5 v i ik dc input diode current 20 ma i ok dc output diode current 20 ma i o dc output current 25 ma i cc or i gnd dc v cc or ground current 50 ma p d power dissipation 300 mw t stg storage temperature -65 to +150 c t l lead temperature (10 sec) 265 c symbol parameter value unit v cc supply voltage 2 to 6 v v i input voltage 0 to v cc v v o output voltage 0 to v cc v t op operating temperature -55 to 125 c t r , t f input rise and fall time v cc = 2.0v 0 to 1000 ns v cc = 4.5v 0 to 500 ns v cc = 6.0v 0 to 400 ns
m54hc238 4/10 table 5: dc specifications table 6: ac electrical characteristics (c l = 50 pf, input t r = t f = 6ns) symbol parameter test conditions value unit v cc (v) t a = 25c -40 to 85c -55 to 125c min. typ. max. min. max. min. max. v ih high level input voltage 2.0 1.5 1.5 1.5 v 4.5 3.15 3.15 3.15 6.0 4.2 4.2 4.2 v il low level input voltage 2.0 0.5 0.5 0.5 v 4.5 1.35 1.35 1.35 6.0 1.8 1.8 1.8 v oh high level output voltage 2.0 i o =-20 a 1.9 2.0 1.9 1.9 v 4.5 i o =-20 a 4.4 4.5 4.4 4.4 6.0 i o =-20 a 5.9 6.0 5.9 5.9 4.5 i o =-4.0 ma 4.18 4.31 4.13 4.10 6.0 i o =-5.2 ma 5.68 5.8 5.63 5.60 v ol low level output voltage 2.0 i o =20 a 0.0 0.1 0.1 0.1 v 4.5 i o =20 a 0.0 0.1 0.1 0.1 6.0 i o =20 a 0.0 0.1 0.1 0.1 4.5 i o =4.0 ma 0.17 0.26 0.33 0.40 6.0 i o =5.2 ma 0.18 0.26 0.33 0.40 i i input leakage current 6.0 v i = v cc or gnd 0.1 1 1 a i cc quiescent supply current 6.0 v i = v cc or gnd 44080 a symbol parameter test conditions value unit v cc (v) t a = 25c -40 to 85c -55 to 125c min. typ. max. min. max. min. max. t tlh t thl output transition time 2.0 30 75 95 110 ns 4.5 8 15 19 22 6.0 7 13 16 19 t plh t phl propagation delay time (a, b, c - y) 2.0 50 150 190 225 ns 4.5 17 30 38 45 6.0 15 26 32 38 t plh t phl propagation delay time (g1 - y) 2.0 50 150 190 225 ns 4.5 17 30 38 45 6.0 15 26 32 38 t plh t phl propagation delay time (g2 - y) 2.0 50 150 190 225 ns 4.5 17 30 38 45 6.0 15 26 32 38
m54hc238 5/10 table 7: capacitive characteristics 1) c pd is defined as the value of the ic?s internal equivalent capacitance which is calculated from the operating current consumption without load. (refer to test circuit). average operating current can be obtained by the following equation. i cc(opr) = c pd x v cc x f in + i cc figure 4: test circuit c l = 50pf or equivalent (includes jig and probe capacitance) r t = z out of pulse generator (typically 50 ? ) symbol parameter test conditions value unit v cc (v) t a = 25c -40 to 85c -55 to 125c min. typ. max. min. max. min. max. c in input capacitance 5.0 5 10 10 10 pf c pd power dissipation capacitance (note 1) 5.0 53 pf
m54hc238 6/10 figure 5: waveform - propagation delay times (f=1mhz; 50% duty cycle)
m54hc238 7/10 dim. mm. inch min. typ max. min. typ. max. a 2.1 2.71 0.083 0.107 a1 3.00 3.70 0.118 0.146 a2 0.63 0.88 1.14 0.025 0.035 0.045 b 1.82 2.39 0.072 0.094 b 0.40 0.45 0.50 0.016 0.018 0.020 b1 0.20 0.254 0.30 0.008 0.010 0.012 d 20.06 20.32 20.58 0.790 0.800 0.810 e 7.36 7.62 7.87 0.290 0.300 0.310 e 2.54 0.100 e1 17.65 17.78 17.90 0.695 0.700 0.705 e2 7.62 7.87 8.12 0.300 0.310 0.320 f 7.29 7.49 7.70 0.287 0.295 0.303 i 3.83 0.151 k 10.90 12.1 0.429 0.476 l 1.14 1.5 0.045 0.059 dilc-16 mechanical data 0056437f
m54hc238 8/10 dim. mm. inch min. typ max. min. typ. max. a 6.75 6.91 7.06 0.266 0.272 0.278 b 9.76 9.94 10.14 0.384 0.392 0.399 c 1.49 1.95 0.059 0.077 d 0.102 0.127 0.152 0.004 0.005 0.006 e 8.76 8.89 9.01 0.345 0.350 0.355 f 1.27 0.050 g 0.38 0.43 0.48 0.015 0.017 0.019 h 6.0 0.237 l 18.75 22.0 0.738 0.867 m 0.33 0.38 0.43 0.013 0.015 0.017 n 4.31 0.170 fpc-16 mechanical data 0016030e 1 8 16 f g d h a b m c n h 9 e l
m54hc238 9/10 table 8: revision history date revision description of changes 01-jun-2004 1 first release 16-jun-2004 2 features updating pag. 1.
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