octal bus transceivers with 3-state outputs 1 wide operating voltage range of 2 v to 6 v high-current 3-state outputs drive bus lines directly or up to 15 lsttl loads low power consumption, 80- a max i cc typical t pd = 12 ns 6-ma output drive at 5 v low input current of 1 a max 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 dir a1 a2 a3 a4 a5 a6 a7 a8 vss v dd oe b1 b2 b3 b4 b5 b6 b7 b8 n, ns, package (top view) description/ordering information these octal bus transceivers are designed for asynchronous bi-direction communication between data buses. the control-function implementation minimizes external timing requirements. the devices allow data transmission from the a bus to the b bus or from the b bus to the a bus, depending on the logic level at the direction-control (dir) input. the output-enable (oe ) input can be used to disable the device so that the buses are effectively isolated. ordering information t a package ? orderable part number top-side marking ?40 c to 85 c pdip ? n tube of 20 ws74hc245n ws74hc245n ?40 c to 85 c hc245 ?40 c to 85 c reel of 2000 hc245 ?40 c to 85 c sop ? ns WS74HC245NSR ?40 c to 85 c hc245
2 function table inputs operation oe dir operation l l b data to a bus l h a data to b bus h x isolation logic diagram (positive logic) dir oe a1 b1 1 2 18 19 to seven other channels absolute maximum ratings over operating free-air temperature range (unless otherwise noted) ? supply voltage range, v dd ?0.5 v to 7 v . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . input clamp current, i ik (v i < 0 or v i > vdd) (see note 1) 20 ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . output clamp current, i ok (v o < 0 or v o > v dd ) (see note 1) 20 ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . continuous output current, i o (v o = 0 to v dd ) 35 ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . continuous current through v dd or vss 70 ma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . package thermal impedance, ja (see note 2): n package 69 c/w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ns package 60 c/w . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . storage temperature range, t stg ?65 c to 150 c . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ? stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress rating s only, and functional operation of the device at these or any other conditions beyond those indicated under ?recommended operating conditions? is not implied. exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. notes: 1. the input and output voltage ratings may be exceeded if the input and output current ratings are observed. 2. the package thermal impedance is calculated in accordance with jesd 51-7. octal bus transceivers with 3-state outputs
3 recommended operating conditions (see note 3) ws74hc245 unit min nom max unit v dd supply voltage 2 5 6 v v high-level input voltage v dd = 2 v 1.5 v v ih high-level input voltage v dd = 4.5 v 3.15 v ih v dd = 6 v 4.2 v low-level input voltage v dd = 2 v 0.5 v v il low-level input voltage v dd = 4.5 v 1.35 v il v dd = 6 v 1.8 v i input voltage 0 v dd v v o output voltage 0 v dd v t/ v input transition rise/fall time v dd = 2 v 1000 ns t/ v input transition rise/fall time v dd = 4.5 v 500 ns v dd = 6 v 400 t a operating free-air temperature ?40 85 c note 3: all unused inputs of the device must be held at v dd or vss to ensure proper device operation. electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) parameter test conditions v c t a = 25 c ws74hc245 unit parameter test conditions v dd min typ max min max unit v v = v or v i = ?20 a 2 v 1.9 1.998 1.9 v v v = v or v i oh = ?20 a 4.5 v 4.4 4.499 4.4 v v oh v i = v ih or v il oh 6 v 5.9 5.999 5.9 v oh iih il i oh = ?6 ma 4.5 v 3.98 4.3 3.84 i oh = ?7.8 ma 6 v 5.48 5.8 5.34 v v = v or v i = 20 a 2 v 0.002 0.1 0.1 v v v = v or v i ol = 20 a 4.5 v 0.001 0.1 0.1 v v ol v i = v ih or v il ol 6 v 0.001 0.1 0.1 v ol iih il i ol = 6 ma 4.5 v 0.17 0.26 0.33 i ol = 7.8 ma 6 v 0.15 0.26 0.33 i i dir or oe v i = v dd or 0 6 v 0.1 100 1000 na i oz a or b v o = v dd or 0 6 v 0.01 0.5 5 a i cc v i = v dd or 0, i o = 0 6 v 8 80 a c i dir or oe 2 v to 6 v 3 10 10 pf octal bus transceivers with 3-state outputs
4 switching characteristics over recommended operating free-air temperature range, c l = 50 pf (unless otherwise noted) (see figure 1) parameter from to v t a = 25 c ws74hc245 unit parameter from (input) to (output) v dd min typ max min max unit t a or b b or a 2 v 40 105 130 ns t pd a or b b or a 4.5 v 15 21 26 ns pd 6 v 12 18 22 t oe a or b 2 v 125 230 290 ns t en oe a or b 4.5 v 23 46 58 ns en 6 v 20 39 49 t oe a or b 2 v 74 200 250 ns t dis oe a or b 4.5 v 25 40 50 ns dis 6 v 21 34 43 t a or b 2 v 20 60 75 ns t t a or b 4.5 v 8 12 15 ns t 6 v 6 10 13 switching characteristics over recommended operating free-air temperature range, c l = 150 pf (unless otherwise noted) (see figure 1) parameter from to v t a = 25 c ws74hc245 unit parameter from (input) to (output) v dd min typ max min max unit t a or b b or a 2 v 54 135 170 ns t pd a or b b or a 4.5 v 18 27 34 ns pd 6 v 15 23 29 t oe a or b 2 v 150 270 335 ns t en oe a or b 4.5 v 31 54 67 ns en 6 v 25 46 56 t a or b 2 v 45 210 265 ns t t a or b 4.5 v 17 42 53 ns t 6 v 13 36 45 operating characteristics, t a = 25 c parameter test conditions typ unit c pd power dissipation capacitance per transceiver no load 40 pf octal bus transceivers with 3-state outputs
5 parameter measurement information voltage waveform input rise and fall times 50% 50% 10% 10% 90% 90% v dd 0 v t r t f input voltage waveforms propagation delay and output transition times 50% 50% 50% 10% 10% 90% 90% v dd v oh v ol 0 v t r t f input in-phase output 50% t plh t phl 50% 50% 10% 10% 90% 90% v oh v ol t r t f t phl t plh out-of-phase output 50% 10% 90% v dd v dd v ol 0 v output control (low-level enabling) output waveform 1 (see note b) 50% t pzl t plz voltage waveforms enable and disable times for 3-state outputs v oh 0 v 50% 50% t pzh t phz output waveform 2 (see note b) v cc test point from output under test c l (see note a) r l v cc s1 s2 load circuit parameter c l t pzh t pd or t t t dis t en t pzl t phz t plz 1 k ? 1 k ? 50 pf or 150 pf 50 pf open closed r l s1 closed open s2 open closed closed open 50 pf or 150 pf open open ?? notes: a. c l includes probe and test-fixture capacitance. b. waveform 1 is for an output with internal conditions such that the output is low except when disabled by the output control. waveform 2 is for an output with internal conditions such that the output is high except when disabled by the output control. c. phase relationships between waveforms were chosen arbitrarily. all input pulses are supplied by generators having the followi ng characteristics: prr 1 mhz, z o = 50 ? , t r = 6 ns, t f = 6 ns. d. the outputs are measured one at a time with one input transition per measurement. e. t plz and t phz are the same as t dis . f. t pzl and t pzh are the same as t en . g. t plh and t phl are the same as t pd . figure 1. load circuit and voltage waveforms octal bus transceivers with 3-state outputs
1 2, 3, 4, 5, 6, 7, 8, 9 10 18, 17, 16, 15, 14, 13, 12, 11 19 20 dir a 1 ? a8 v ss b 1 ? b8 oe v dd direction control data inputs / outputs ground (0v) data inputs / outputs output enable input (active low) positive power supply pad diagram the coordinate of low left corner for each pad b2 (-741.9, -722.4) a3 ( 651.8, -503.2) b8 (-267.8, 657.6) b1 (-558.3, -747.1) a4 ( 651.8, -124.2) b7 (-466.6, 657.6) oe (-288.0, -747.1) a5 ( 651.8, 74.6) b6 (-741.9, 506.6) vdd(-111.4, -742.5) a6 ( 651.8, 454.0) b5 (-741.9, 236.8) dir ( 85.8, -747.1) a7 ( 559.5, 657.6) b4 (-741.9, -143.4) a1 ( 262.6, -747.1) a8 ( 179.3, 657.6) b3 (-741.9, -342.2) a2 ( 642.8, -747.1) vss ( 2.7, 658.6) v dd b2 b1 oe dir a1 a2 a3 a4 a5 a6 a7 a8 vss b8 b7 b6 b5 b4 b3 hc245 pad size = 90 um x 90 um die size = 69 mil x 72 mil octal bus transceivers with 3-state outputs 6
octal bus transceivers with 3-state outputs 7
octal bus transceivers with 3-state outputs 8
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