74vhc244 octal bus buffer with 3 state outputs (non inverted) june 1999 n high speed: t pd = 3.9 ns (typ.) at v cc = 5v n low power dissipation: i cc = 4 m a (max.) at t a = 25 o c n high noise immunity: v nih = v nil = 28% v cc (min.) n power down protection on inputs n symmetrical output impedance: |i oh | = i ol = 8 ma (min) n balanced propagation delays: t plh @ t phl n operating voltage range: v cc (opr) = 2v to 5.5v n pin and function compatible with 74 series 244 n improved latch-up immunity n low noise v olp = 0.9v (max.) description the 74vhc244 is an advanced high speed cmos octal bus buffer (3-state) fabricated with sub-micron silicon gate and double-layer metal wiring c 2 mos technology. g output enable governs four bus buffers. this device is designed to be used with 3 state memory address drivers, etc. power down protection is provided on all inputs and 0 to 7v can be accepted on inputs with no regard to the supply voltage. this device can be used to interface 5v to 3v. all inputs and outputs are equipped with protection circuits against static discharge, giving them 2kv esd immunity and transient excess voltage. pin connection and iec logic symbols order codes : 74vhc244m 74vhc244t m (micro package) t (tssop package) ? 1/8
input equivalent circuit truth table input output ganyn lll lhh hxz x: "h" or "l" z: high impedance pin description pin no symbol name and function 1 1g output enable input 2, 4, 6, 8 1a1 to 1a4 data inputs 9, 7, 5, 3 2y1 to 2y4 data outputs 11, 13, 15, 17 2a1 to 2a4 data inputs 18, 16, 14, 12 1y1 to 1y4 data outputs 19 2g output enable input 10 gnd ground (0v) 20 v cc positive supply voltage absolute maximum ratings symbol parameter value unit v cc supply voltage -0.5 to +7.0 v v i dc input voltage -0.5 to +7.0 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 75 ma t stg storage temperature -65 to +150 o c t l lead temperature (10 sec) 300 o c absolute maximum ratings are those values beyond which damage to the device may occur. functional operation under these conditi on is not implied. recommended operating conditions symbol parameter value unit v cc supply voltage 2.0 to 5.5 v v i input voltage 0 to 5.5 v v o output voltage 0 to v cc v t op operating temperature -40 to +85 o c dt/dv input rise and fall time (see note 1) (v cc = 3.3 0.3v) (v cc = 5.0 0.5v) 0 to 100 0 to 20 ns/v ns/v 1) v in from 30% to 70% of v cc 74vhc244 2/8
ac electrical characteristics (input t r = t f =3 ns) symbol parameter test condition value unit v cc (v) c l (pf) t a = 25 o c -40 to 85 o c min. typ. max. min. max. t plh t phl propagation delay time 3.3 (*) 15 5.8 8.4 1.0 10.0 ns 3.3 (*) 50 8.3 11.9 1.0 13.5 5.0 (**) 15 3.9 5.5 1.0 6.5 5.0 (**) 50 5.4 7.5 1.0 8.5 t pzl t pzh output enable time 3.3 (*) 15 r l = 1k w 6.6 10.6 1.0 12.5 ns 3.3 (*) 50 r l = 1k w 9.1 14.1 1.0 16.0 5.0 (**) 15 r l = 1k w 4.7 7.3 1.0 8.5 5.0 (**) 50 r l = 1k w 6.2 9.3 1.0 10.5 t plz t phz output disable time 3.3 (*) 50 r l = 1k w 10.3 14.0 1.0 16.0 ns 5.0 (**) 50 r l = 1k w 6.7 9.2 1.0 10.5 t oslh t oshl output to output skew time (note 1) 3.3 (*) 50 1.5 1.5 ns 5.0 (**) 50 1.0 1.0 (*) voltage range is 3.3v 0.3v (**) voltage range is 5v 0.5v note 1: parameter guaranteed by design. t solh = |t plhm - t plhn |, t sohl = |t phlm - t phln | dc specifications symbol parameter test conditions value unit v cc (v) t a = 25 o c -40 to 85 o c min. typ. max. min. max. v ih high level input voltage 2.0 1.5 1.5 v 3.0 to 5.5 0.7v cc 0.7v cc v il low level input voltage 2.0 0.5 0.5 v 3.0 to 5.5 0.3v cc 0.3v cc v oh high level output voltage 2.0 i o =-50 m a 1.9 2.0 1.9 v 3.0 i o =-50 m a 2.9 3.0 2.9 4.5 i o =-50 m a 4.4 4.5 4.4 3.0 i o =-4 ma 2.58 2.48 4.5 i o =-8 ma 3.94 3.8 v ol low level output voltage 2.0 i o =50 m a 0.0 0.1 0.1 v 3.0 i o =50 m a 0.0 0.1 0.1 4.5 i o =50 m a 0.0 0.1 0.1 3.0 i o =4 ma 0.36 0.44 4.5 i o =8 ma 0.36 0.44 i oz high impedance output leakage current 5.5 v i = v ih or v il v o = v cc or gnd 0.25 2.5 m a i i input leakage current 0 to 5.5 v i = 5.5v or gnd 0.1 1.0 m a i cc quiescent supply current 5.5 v i = v cc or gnd 4 40 m a 74vhc244 3/8
capacitive characteristics symbol parameter test conditions value unit t a = 25 o c -40 to 85 o c min. typ. max. min. max. c in input capacitance 4 10 10 pf c out output capacitance 6 pf c pd power dissipation capacitance (note 1) 19 pf 1) c pd is defined as the value of the ics 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 v cc f in + i cc /48(per gate) test circuit test switch t plh , t phl open t pzl , t plz v cc t pzh , t phz gnd c l = 15/50 pf or equivalent (includes jig and probe capacitance) r l = r 1 = 1k w or equivalent r t = z out of pulse generator (typically 50 w ) dynamic switching characteristics symbol parameter test conditions value unit v cc (v) t a = 25 o c -40 to 85 o c min. typ. max. min. max. v olp dynamic low voltage quiet output (note 1, 2) 5.0 c l = 50 pf 0.6 0.9 v v olv -0.9 -0.6 v ihd dynamic high voltage input (note 1, 3) 5.0 3.5 v ild dynamic low voltage input (note 1, 3) 5.0 1.5 1) worst case package. 2) max number of outputs defined as (n). data inputs are driven 0v to 5.0v, (n -1) outputs switching and one output at gnd. 3) max number of data inputs (n) switching. (n-1) switching 0v to 5.0v. inputs under test switching: 5.0v to threshold (v ild ), 0v to threshold (v ihd ), f=1mhz. 74vhc244 4/8
waveform 1: propagation delays (f=1mhz; 50% duty cycle) waveform 2: output enable and disable time (f=1mhz; 50% duty cycle) 74vhc244 5/8
dim. mm inch min. typ. max. min. typ. max. a2.650.104 a1 0.10 0.20 0.004 0.007 a2 2.45 0.096 b 0.35 0.49 0.013 0.019 b1 0.23 0.32 0.009 0.012 c0.50 0.020 c1 45 (typ.) d 12.60 13.00 0.496 0.512 e 10.00 10.65 0.393 0.419 e1.27 0.050 e3 11.43 0.450 f 7.40 7.60 0.291 0.299 l 0.50 1.27 0.19 0.050 m0.750.029 s 8 (max.) p013l so-20 mechanical data 74vhc244 6/8
dim. mm inch min. typ. max. min. typ. max. a1.10.433 a1 0.05 0.10 0.15 0.002 0.004 0.006 a2 0.85 0.9 0.95 0.335 0.354 0.374 b 0.19 0.30 0.0075 0.0118 c 0.09 0.2 0.0035 0.0079 d 6.4 6.5 6.6 0.252 0.256 0.260 e 6.25 6.4 6.5 0.246 0.252 0.256 e1 4.3 4.4 4.48 0.169 0.173 0.176 e 0.65 bsc 0.0256 bsc k0 o 4 o 8 o 0 o 4 o 8 o l 0.50 0.60 0.70 0.020 0.024 0.028 c e b a2 a e1 d 1 pin 1 identification a1 l k e tssop20 mechanical data 74vhc244 7/8
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