1 white electronic designs corporation ? (602) 437-1520 ?www.whiteedc.com white electronic designs edi88257ca may 2000 rev. 2 white electronic designs corp. reserves the right to change products or speci cations without notice. 256kx8 monolithic sram features ? access times of 20, 25, 35, 45, 55ns ? data retention function (lpa versions) ? ttl compatible inputs and outputs ? fully static, no clocks ? organized as 256kx8 ? commercial, industrial and military temperature ranges ? jedec approved evolutionary pinout ? 32 pin ceramic dip, 0.6 mils wide (package 9) ? single +5v (10%) supply operation block diagram figure 1 ? pin configuration the edi88257ca is a 2 megabit 256kx8 bit monolithic cmos static ram. the 32 pin dip pinout adheres to the jedec evolutionary standard for the two megabit device. the device is upgradeable to the 512kx8 sram, the edi88512ca. pin 1 becomes the higher order address. a low power version, edi88257lpa, offers a data retention function for battery back-up opperation. military product is available compliant to appendix a of mil-prf-38535. this product is subject to change without notice. 32 dip top view 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 v cc a15 a17 we# a13 a8 a9 a11# oe a10 cs# i/o7 i/o6 i/o5 i/o4 i/o3 nc a16 a14 a12 a7 a6 a5 a4 a3 a2 a1 a0 i/o0 i/o1 i/o2 v ss memory array address buffer address decoder i/o circuits a 0-17 i/o 0-7 we# cs oe# pin description i/o0-7 data inputs/outputs a0-17 address inputs we# write enable cs# chip selects oe# output enable v cc power (+5v 10%) v ss ground nc not connected
2 white electronic designs corporation ? (602) 437-1520 ?www.whiteedc.com white electronic designs edi88257ca may 2000 rev. 2 white electronic designs corp. reserves the right to change products or speci cations without notice. absolute maximum ratings parameter value unit voltage on any pin relative to vss -0.5 to 7.0 v operating temperature t a (ambient) industrial -40 to +85 c military -55 to +125 c storage temperature, ceramic -65 to +150 c power dissipation 1.5 w output current 20 ma junction temperature, t j 175 c note: stress greater than those listed under ?absolute maximum ratings? may cause permanent damage to the device. this is a stress rating only and func tion al operation of the device at these or any other conditions greater than those in di cat ed in the operational sections of this spec i ca tion is not implied. exposure to absolute maximum rating conditions for extended periods may affect reliability. recommended operating conditions parameter symbol min typ max unit supply voltage v cc 4.5 5.0 5.5 v supply voltage v ss 000v input high voltage v ih 2.2 ? v cc +0.5 v input low voltage v il -0.3 ? +0.8 v truth table oe# cs# we# mode output power x h x standby high z i cc2 , i cc3 h l h output deselect high z i cc1 l l h read data out i cc1 x l l write data in i cc1 input pulse levels v ss to 3.0v input rise and fall times 5ns input and output timing levels 1.5v output load figure 1 note: for t ehqz , t ghqz and t wlqz , cl = 5pf figure 2 30pf 480 vcc q figure 1 figure 2 255 5pf 480 vcc q 255 ac test conditions dc characteristics v cc = 5v, t a = +25c parameter symbol conditions min typ max units input leakage current i li v in = 0v to v cc -10 ? +10 a output leakage current i lo v i/o = 0v to v cc -10 ? +10 a operating power supply current i cc1 we#, cs# = v il , i i/o = 0ma, min cycle (20-25ns) ? 225 ma (35-55ns) ? 200 ma standby (ttl) power supply current i cc2 cs# v ih , v in v il , v in v ih ?60ma full standby power supply current i cc3 cs# v cc -0.2v v in vcc -0.2v or v in 0.2v c??25ma lp ? ? 20 ma output low voltage v ol i ol = 8.0ma ? ? 0.4 v output high voltage v oh i oh = -4.0ma 2.4 ? ? v capacitance parameter symbol condition max unit address lines c i v in = vcc or vss, f = 1.0mhz 12 pf data lines c o v out = vcc or vss, f = 1.0mhz 14 pf these parameters are sampled, not 100% tested.
3 white electronic designs corporation ? (602) 437-1520 ?www.whiteedc.com white electronic designs edi88257ca may 2000 rev. 2 white electronic designs corp. reserves the right to change products or speci cations without notice. ac characteristics ? read cycle v cc = 5.0v, vss = 0v, -55c t a +125c parameter symbol 20ns 25ns 35ns 45ns 55ns units jedec alt. min max min max min max min max min max read cycle time t avav t rc 20 25 35 45 55 ns address access time t avqv t aa 20 25 35 45 55 ns chip enable access time t elqv t acs 20 25 35 45 55 ns chip enable to output in low z (1) t elqx t clz 33333ns chip disable to output in high z (1) t ehqz t chz 0 8 010015020020ns output hold from address change t avqx t oh 00000ns output enable to output valid t glqv t oe 10 12 15 25 25 ns output enable to output in low z (1) t glqx t olz 00000ns output disable to output in high z(1) t ghqz t ohz 0 8 010015020020ns 1. this parameter is guaranteed by design but not tested. ac characteristics ? write cycle v cc = 5.0v, v ss = 0v, -55c t a +125c parameter symbol 20ns 25ns 35ns 45ns 55ns units jedec alt. min max min max min max min max min max write cycle time t avav t wc 20 25 35 45 55 ns chip enable to end of write t elwh t eleh t cw t cw 15 15 17 17 25 25 30 30 30 30 ns ns address setup time t avwl t avel t as t as 0 0 0 0 0 0 0 0 0 0 ns ns address valid to end of write t avwh t aveh t aw t aw 15 15 17 17 25 25 30 30 30 30 ns ns write pulse width t wlwh t wleh t wp t wp 15 15 17 17 25 25 30 30 30 30 ns ns write recovery time t whax t ehax t wr t wr 0 0 0 0 0 0 0 0 0 0 ns ns data hold time t whdx t ehdx t dh t dh 0 0 0 0 0 0 0 0 0 0 ns ns write to output in high z (1) t wlqz t whz 030030025030030ns data to write time t dvwh t dveh t dw t dw 10 10 12 12 20 20 25 25 25 25 ns ns output active from end of write (1) t whqx t wlz 00000ns 1. this parameter is guaranteed by design but not tested.
4 white electronic designs corporation ? (602) 437-1520 ?www.whiteedc.com white electronic designs edi88257ca may 2000 rev. 2 white electronic designs corp. reserves the right to change products or speci cations without notice. write cycle 2, cs# controlled t aveh t eleh t ehax t wleh t dveh t ehdx t avav data valid high z data out t avel address data in we# cs# address data i/o read cycle 1 (we# high; oe#, cs# low) t avqx t avqv t avav data 2 address 1 address 2 data 1 address data out read cycle 2 (we# high) t avqv t elqv t glqv t elqx t glqx t avav t ehqz t ghqz oe# cs# figure 2 ? timing waveform - read cycle figure 4 ? write cycle - cs# controlled figure 3 ? write cycle - we# controlled address data in write cycle 1, we# controlled t avwh t elwh t whax t wlwh t dvwh t wlqz t whqx t avwl t whdx t avav data valid high z we# cs# data out
5 white electronic designs corporation ? (602) 437-1520 ?www.whiteedc.com white electronic designs edi88257ca may 2000 rev. 2 white electronic designs corp. reserves the right to change products or speci cations without notice. data retention characteristics (edi88512lp only) -55c t a +125c characteristic low power version only sym conditions min typ max units data retention voltage data retention quiescent current v cc i ccdr v cc = 2.0v cs# v cc -0.2v 2 ? ? ? ? 2 v a chip disable to data retention time operation recovery time t cdr t r v in v cc -0.2v or v in 0.2v 0 t avav ? ? ? ? ns ns figure 5 ? data retention - cs# controlled data retention mode cs# = v cc -0.2v v cc cs# t cdr v cc 4.5v 4.5v t r data retention, cs# controlled
6 white electronic designs corporation ? (602) 437-1520 ?www.whiteedc.com white electronic designs edi88257ca may 2000 rev. 2 white electronic designs corp. reserves the right to change products or speci cations without notice. package 9: 32 pin sidebrazed ceramic dip (600mils wide) all dimensions are in inches pin 1 indicator 0.020 0.016 0.200 0.125 0.100 typ 15 x 0.100 = 1.500 0.155 0.115 1.616 1.584 0.061 0.017 0.600 nom 0.060 0.040 0.620 0.600 ordering information white electronic designs sram organization, 256kx8 technology: ca = cmos standard power lpa = low power access time (ns) package type: c = 32 lead sidebrazed dip, 600 mil (package 9) device grade: b = mil-std-883 compliant m = military screened -55c to +125c i = industrial -40c to +85c c = commercial 0c to +70c edi 8 8 257 ca x x x
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