1 ps7018b 03/17/00 product description pericom semiconductor?s pi5c series of logic circuits are produced using the company?s advanced submicron cmos technology, achieving industry leading performance. the pi5c3257 is a quad 2:1 multiplexer/demultiplexer with three- state outputs that is pinout and function compatible with the pi74fct257t, 74f257, and 74als/as/ls257. inputs can be connected to outputs with low on resistance (5 ohms) with no additional ground bounce noise or propagation delay. logic block diagram pi5c3257 quad 2:1 mux/demux busswitch 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 product features: ? near zero propagation delay ? 5ohm switches connect inputs to outputs ? direct bus connection when switches are on ? ultra low quiescent power (0.2a typical) ? ideally suited for notebook applications ? pin compatible with 74 series 257 logic devices ? packages available: ? 16-pin 150 mil wide plastic qsop (q) ? 16-pin 300 mil wide plastic soic (s) ? 16-pin 150 mil wide plastic soic (w) ? 16-pin 173 mil wide plastictssop (l) ? 20-pin 150 mil wide plastic tssop (r) 16-pin product configuration 20-pin product configuration product pin description e s ya yb yc yd function h x hi-z hi-z hi-z hi-z disable l l ia0 ib0 ic0 id0 s = 0 l h ia1 ib1 ic1 id1 s = 1 truth table (1) note: 1. h = high voltage level l = low voltage level e ia 0 ia 1 ib 0 ib 1 ic 0 ic 1 id 0 id 1 s ya yb yc yd v cc s 1 e ia0 2 id0 ia1 3 id1 ya 4 yd ib0 5 16 ic0 ib1 6 15 ic1 yb 7 14 yc 8 13 12 gnd 11 10 9 16-pin l, q, s, w v cc nc 1 e s 2 id1 ia0 3 id0 ia1 4 yd ya 5 20 ib0 6 19 ic0 ib1 7 18 yc 8 17 16 gnd 15 14 13 yb 9 10 nc nc 12 11 nc ic1 20-pin r pin name description ian-idn data inputs s select inputs e enable ya-yd data outputs gnd ground v cc power nc no connect
pi5c3257 quad 2:1 mux/demux busswitch 2 ps7018b 03/17/00 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 storage temperature ............................................................ ?65c to +150c ambient temperature with power applied ............................ ?40c to +85c supply voltage to ground potential (inputs & vcc only) ...... ?0.5v to +7.0v supply voltage to ground potential (outputs & d/o only) ... ?0.5v to +7.0v dc input voltage .................................................................... ?0.5v to +7.0v dc output current .............................................................................. 120ma power dissipation .................................................................................. 0.5w note: stresses greater than those listed under maximum ratings may cause permanent damage to the device. this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational sections of this specifica- tion is not implied. exposure to absolute maximum rating conditions for extended periods may affect reli- ability. dc electrical characteristics (over the operating range, t a = ?40c to +85c, v cc = 5v 5%) parameters description test conditions (1) min. typ (2) max. units v ih input high voltage guaranteed logic high level 2.0 v v il input low voltage guaranteed logic low level ?0.5 0.8 v i ih input high current v cc = max., v in = v cc 1 a i il input low current v cc = max., v in = gnd 1 a i ozh high impedance output current 0 i, y v cc 1 a v ik clamp diode voltage v cc = min., i in = ?18 ma ?0.7 ?1.2 v i os short circuit current (3) i (y) = 0v, y (i) = v cc 100 ma v h input hysteresis at control pins 150 mv r on switch on resistance (4) v cc = min., v in = 0.0v, i on = 48ma 5 7 ohm v cc = min., v in = 2.4v, i on = 15ma 10 15 capacitance (t a = 25c, f = 1 mhz) parameters (5) description test conditions typ max. units c in input capacitance v in = 0v 6 pf c off in/yn capacitance, switch off v in = 0v 6 pf c on in/yn capacitance, switch on v in = 0v 14 pf notes: 1. for max. or min. conditions, use appropriate value specified under electrical characteristics for the applicable device type. 2. typical values are at v cc = 5.0v, t a = 25c ambient and maximum loading. 3. not more than one output should be shorted at one time. duration of the test should not exceed one second. 4. measured by the voltage drop between i and y pin at indicated current through the switch. on resistance is determined by the lower of the voltages on the two (i,y) pins. 5. this parameter is determined by device characterization but is not production tested. maximum ratings (above which the useful life may be impaired. for user guidelines, not tested.)
pi5c3257 quad 2:1 mux/demux busswitch 3 ps7018b 03/17/00 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 power supply characteristics parameters description test conditions (1) min. typ (2) max. units i cc quiescent power v cc = max. v in = gnd or v cc 0.1 3.0 a supply current di cc supply current per v cc = max. v in = 3.4v (3) 2.5 ma input @ ttl high i ccd supply current per v cc = max., 0.25 ma/ input per mhz (4) i and y pins open mhz be = gnd control input toggling 50% duty cycle notes: 1. for max. or min. conditions, use appropriate value specified under electrical characteristics for the applicable device. 2. typical values are at v cc = 5.0v, +25c ambient. 3. per ttl driven input (v in = 3.4v, control inputs only); i and y pins do not contribute to i cc . 4. this current applies to the control inputs only and represent the current required to switch internal capacitance at the spec ified frequency. the i and y inputs generate no significant ac or dc currents as they transition. this parameter is not tested, but i s guaranteed by design. switching characteristics over operating range pi5c3257 com. parameters description conditions (1) min. max. units t iy propagation delay (2,3) c l = 50 pf 0.25 in to yn r l = 500ohm t sy bus select time 0.5 5.2 ns sn to yn t pzh bus disable time 0.5 4.8 t pzl e to yn t phz bus disable time 0.5 5.0 t plz e to yn notes: 1. see test circuit and waveforms. 2. this parameter is guaranteed but not tested on propagation delays. 3. the bus switch contributes no propagational delay other than the rc delay of the on resistance of the switch and the load capacitance. the time constant for the switch alone is of the order of 0.25ns for 50pf load. since this time constant is much smaller than the rise/ fall times of typical driving signals, it adds very little propagational delay to the system. propagational delay of the bus switch when used in a system is determined by the driving circuit on the driving side of the switch and its interaction with the load on the driven side. pericom semiconductor corporation 2380 bering drive ? san jose, ca 95131 ? 1-800-435-2336 ? fax (408) 435-1100 ? http://www.pericom.com
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