1 ps8472a 05/02/00 product pin configuration product pin description pin name description be0, be1 bus enable input (active low) a0?9 bus a b0?9 bus b gnd ground v cc power function be0 a 0?a4 disconnect h hi-z connect l b 0?4 truth table (1) notes: 1. h = high voltage level l = low voltage level hi-z = high impedance logic block diagram 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 1 2345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901212345678901234567890123456789012 12345678901 2 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 PI2BV3877 2.5v, 10-bit, 2-port 266 mhz ddr busswitch product description pericom semiconductor?s pi2b series of logic circuits are produced using the company?s advanced submicron cmos technology, achieving industry leading performance. the PI2BV3877 is a 10-bit, 2.5 volt two-port bus switch designed with a low on resistance allowing inputs to be connected directly to outputs. the bus switch creates no additional propagational delay or additional ground bounce noise. the switches are turned on by the bus enable (be n ) input signals. the PI2BV3877 switch is intended for 266 mhz ddr(x4) memory module applications. product features ? used in x4 ddr modules ? near zero propagation delay ? 20 ohm switches connect inputs to outputs ? fast switching speed ?3ns (max.) ? low off capacitance (3pf) ? pull-down on b output ? pull-up on switch enable ? packages available: ? 24-pin 150 mil wide plastic qsop (q) ? 24-pin 173 mil wide plastic tssop (l) function be1 a 5?a9 disconnect h hi-z connect l b 5?b9 v cc b 0 b 1 b 2 b 3 b 4 b 5 b 6 b 7 b 8 b 9 be 1 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 be 0 a 0 a 1 a 2 a 3 a 4 a 5 a 6 a 7 a 8 a 9 gnd 24-pin q, l be0 a 4 a 0 b 4 b 0 vcc be1 a 9 a 5 b 9 b 5 vcc
2 ps8472a 05/02/00 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 PI2BV3877 2.5v, 10-bit, 2-port 266 mhz ddr busswitch dc electrical characteristics (over the operating range, t a = 0c to +85c, v cc = 2.3v to 2.7v) parameters description test conditions (1) min. typ. (2) max. units v ih input high voltage (be0, be1) guaranteed logic high level 1.6 v cc + 0.3 v il input low voltage (be0, be1) g uaranteed logic low level ?0.3 0.9 i ozh high impedance output current b @ 2.5v 250 a v ik clamp diode voltage v cc = min., i in = ?18ma ?1.2 v r on switch on resistance (4) v cc = min., v in = 0.9v, i on = 20ma 17 33 v cc = min., v in = 1.6v, i on = 15ma 22 30 r pu pull-up resistance 115 150 200 storage temperature ............................................................... ?65c to +150c ambient temperature with power applied .............................. ?40c to +85c supply voltage to ground potential (inputs & v cc only) ........ ?0.5v to +4.6v supply voltage to ground potential (outputs & d/o only) ...... ?0.5v to +4.6v dc input voltage ....................................................................... ?0.5v to +4.6v 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 indi- cated in the operational sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. capacitance (t a = 25c, f = 1 mhz) parameters (4) description test conditions typ. units c in input capacitance v in = 0v 3 c off a capacitance, switch off v in = 0v 3 pf c on (a/b) a/b capacitance, switch on v in = 0v 7 maximum ratings (above which the useful life may be impaired. for user guidelines, not tested.) w notes: 1. for max. or min. conditions, use appropriate value specified under electrical characteristics for the applicable device ty pe. 2. typical values are at v cc = 2.5v, t a = 25c ambient and maximum loading. 3. measured by the voltage drop between a and b pin at indicated current through the switch. on resistance is determined by the lower of the voltages on the two (a,b) pins. 4. this parameter is determined by device characterization but is not production tested. v power supply characteristics parameters description test conditions (1) min. typ. (2) max. units i cc quiescent power v cc = max. v in = v cc C10 m a supply current v in = gnd C 56 ma 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 = 2.5v, +25c ambient. 3. per ttl driven input (control input only); a and b pins do not contribute to i cc .
3 ps8472a 05/02/00 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 PI2BV3877 2.5v, 10-bit, 2-port 266 mhz ddr busswitch switching characteristics over operating range 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 cap acitance. the time constant for the switch alone is of the order of 1ns 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. s r e t e m a r a pn o i t p i r c s e ds n o i t i d n o c ) 3 , 2 ( 7 7 8 3 v b 2 i p s t i n u . m o c . n i m. x a m t h l p t l h p y a l e d n o i t a g a p o r p ) 3 , 2 ( x a o t x b , x b o t x a c l , f p 0 3 = r l 0 0 5 = , w r0 0 5 = w 1 s n t h z p t l z p e m i t e l b a n e s u b x b r o x a o t e b 13 15 . 3 t z h p t z l p e m i t e l b a s i d s u b x b r o x a o t e b 13 18 . 3 parameter measurements voltage waveforms propagation delay times voltage waveforms enable and disable times t s e t1 s t d p n e p o t z l p t / l z p v x 2 c c t z h p t / h z p d n g notes: 1. c l includes probe and jig capacitance. 2. 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. 3. all input pulses are supplied by generators having the following characteristics: prr<10mhz, z o = 50 w , t r 2ns, t f 2ns. 4. the outputs are measured one at a time with one transition per measurement. 5. t plz and t phz are the same as t dis . 6. t pzl and t pzh are the same as t en . 7. t plh and t phl are the same as t pd . 500 w 500 w gnd 2xv cc open s1 load circuit from output under test c l = 30pf (see note 1) input t plh t phl v cc v cc /2 v cc /2 v cc /2 v cc /2 0v output v oh v ol t pzl output control (low level enabling) 0v v cc /2 v cc /2 v cc /2 v cc /2 t plz t phz v ol v oh 0v t pzh +0.15v -0.15v output waveform 1 s1 at 2xv cc (see note 2) output waveform 2 s1 at gnd (see note 2) v oh v oh v ol v cc
4 ps8472a 05/02/00 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 1234567890123456789012345678901212345678901234567890123456789012123456789012345678901234567890121234567890123456789012345678901 2123456789012 PI2BV3877 2.5v, 10-bit, 2-port 266 mhz ddr busswitch pericom semiconductor corporation 2380 bering drive ? san jose, ca 95131 ? 1-800-435-2336 ? fax (408) 435-1100 ? http://www.pericom.com t r a pe g a k c a p - n i pe r u t a r e p m e t q 7 7 8 3 v b 2 i p) q ( p o s q - 4 2 c 5 8 + o t c 0 l 7 7 8 3 v b 2 i p) l ( p o s s t - 4 2 ordering information .337 .344 .053 .069 .004 .010 seating plane .025 typical .005 .010 .228 .244 1 24 .150 .157 .016 .036 x.xx x.xx denotes dimensions in millimeters 0.635 8.56 8.74 1.35 1.75 5.79 6.20 0.406 0.914 0.101 0.254 .008 .012 0.203 0.305 3.81 3.99 0.127 0.254 .033 0.84 0.38 .015 x 45? .303 .311 .047 1.20 .002 .006 seating plane .0256 bsc .018 .030 .004 .008 .252 bsc 1 24 .169 .177 x.xx x.xx denotes controlling dimensions in millimeters 0.05 0.15 6.4 0.45 0.75 0.09 0.20 4.3 4.5 7.7 7.9 0.65 0.19 0.30 .007 .012 max 24-pin qsop (q) 24-pin tssop (l)
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