description the gm76c256c family is a 262,144 bits static random access memory organized as 32,768 words by 8 bits. using a 0.6 u m advanced cmos tech- nology and operated a single 5.0v supply. . advanced circuit techniques provide both high speed and low power consumption. the family can support various operating temerature ranges for user flexibility of system design. . the family has chip select /cs, which allows for device selection and data retention control, and output enable (/oe), which provides fast memory access. thus it is suitable for high speed and low power applications, particularly where battery back-up is required. . 33 pin description i/o0 i/o1 i/o2 i/o3 i/o4 i/o5 i/o6 i/o7 a0 a1 a13 a14 /cs /oe /we memory cell array 512 x 64 x 8 (32k x 8) column select i/o buffer address buffer x decoder 9 512 6 64 64 x 8 8 y decoder a2 . . . . . . . . chip control i/o control pin function a0-a14 address inputs i/o0-i/o7 v cc v ss write enable input output enable input chip select input data input/output power supply ground /oe /cs /we pin configuration block diagram features * high speed : fast access and cycle time 55/70ns max * low power standby and low power operation -standby : 165uw at t a = -25 ~ 85 c (lle) 110uw at t a = 0 ~ 70 c (ll) -operation : 385mw at vcc=5.0v + 0.5v * completely static ram : no clock or timing strobe required * power supply voltage : 5.0v + 0.5v * low data retention voltage : 2.0v(min) * temperature range -gm76c256cl/ll : ( 0 ~ 70 c ) -gm76c256cle/lle : (-25 ~ 85 c ) * package type : jedec standard 28-dip,sop,tsop(i) gm76c256cl/ll 32,768 words x 8 bit cmos static ram lg semicon co.,ltd. (top view) a7 a6 a5 a4 a3 a2 a1 a0 i/o0 v cc /we a13 a8 a9 a11 /oe a10 /cs i/o7 i/o6 i/o5 1 2 3 4 5 6 7 8 9 10 11 12 17 18 19 20 21 22 23 24 25 26 27 28 i/o2 v ss i/o4 i/o3 13 14 15 16 a14 a12 i/o1
gm76c256cl/ll lg semicon absolute maximum ratings 34 /cs h l l *note: x means "don't care". /we x h l /oe x l x input/output hi-z output data input data mode not selected read write l h h hi-z output disable truth table notes: 1. operation at above absolute maximum ratings can adversely affect device reliability. 2. -3.0v at pulse width 50ns max. *1 symbol parameter rating unit 0 ~ 70 t a -25 ~ 85 ambient temperature under bias t stg v sol -65 ~ 150 260, 10 (at lead) storage temperature soldering temperature and time c v cc -0.3 ~ 4.6 supply voltage v v in v i/o -0.3 ~ 4.6 -0.5 ~ v cc + 0.5 input voltage input and output voltage v v p d 1.0 power dissipation w c,s *2 gm76c256cl/ll gm76c256cle/lle recommended dc operating conditions (t a = -25 ~ 85 c ) *note: v il =-3.0v min for pulse width less than 50ns. symbol parameter unit v cc v ih supply voltage input high voltage v v v cc + 0.3 5.0 4.5 v il input low voltage v gm76c256c typ - - min 2.2 -0.3* max 5.5 0.8 c c
gm76c256cl/ll lg semicon 35 dc electrical characteristics (v cc =5.0v + 0.5v , t a = -25 ~ 85 c ) symbol parameter unit i i(l) input leakage current ua i o(l) output leakage current ua v oh high level output voltage v v ol low level output voltage v i cc operating supply current ma i cc1 average operating current ma test conditions v in = 0 to v cc /cs = v ih or /oe = v ih or /we = v il , v < v out < v cc i oh = -1.0ma i ol = 2.1ma /cs = v il , v in = v ih /v il, i i/o = 0ma /cs = v il , v in = v ih /v il i i/o = 0ma t cycle = min, cycle max 1 1 - 0.4 10 70 typ - - - - min -1 -1 2.4 - - - - - *typ. values are measured at 25 c , v cc = 5.0v i ccs1 ma standby current (ttl) /cs = v ih 1.0 - - - - 20 ua - 30 ua - i ccs2 standby current (cmos) /cs < v cc -0.2v(ll) i cc2 average operating current ma 10 - - /cs = v il , v in = v ih /v il i i/o = 0ma t cycle = 1us, cycle gm76c256c - 40 ua - - - 60 ua /cs < v cc -0.2v (l) 0 to +70 c (ll) -25 to +85 c (lle) -25 to +85 c (le) 0 to +70 c (l)
gm76c256cl/ll lg semicon 36 ac operating characteristics (v cc =5.0v + 0.5v , t a = -25 ~ 85 c ) read cycle write cycle symbol parameter unit t wc write cycle time ns t cw chip select to end of write ns t aw address set-up time to end of write ns t as address set-up time ns t wp write pulse width ns t wr write recovery time ns t dw data to write time overlap ns t dh data hold time ns t whz write to output in high-z ns condi- tions *1 *2 t ow output active from end of write ns max min max min 70 60 60 0 50 0 30 0 0 5 - - - - 25 - - - - - gm76c256c-55 gm76c256c-70 55 45 45 0 40 0 25 0 0 5 - - - - 20 - - - - - symbol parameter unit max min t rc read cycle time ns t aa address access time ns t acs chip select access time ns t oe output enable access time ns t oh output hold time ns condi- tions *1 *2 max min t clz chip selection to output in low-z ns t ohz output disable to output in high-z ns t chz chip deselection to output in high-z ns t olz output disable to output in low-z ns 70 - - - 10 70 70 - - 30 10 0 0 5 - 25 25 - gm76c256c-55 gm76c256c-70 55 - - - 10 55 55 - - 25 10 0 0 5 - 20 20 - *1 test conditions. 1. input pulse level : 0.6v to 2.4v 2. tr = tf = 5ns 3. input/output timing reference level : 1.5v 4. output load c l = 100pf + 1ttl load *2 test conditions. 1. input pulse level : 0.6v to 2.4v 2. tr = tf = 5ns 3. input timing reference level : 1.5v 4. output timing reference level : +/-200mv (the level displacement from stable output voltage level) 5. output load c l = 5pf + 1ttl load
gm76c256cl/ll lg semicon 37 timing waveforms d out t rc add valid data read cycle 1 (note 1, 2) high-z valid data previous valid data t oh t aa /cs t rc add read cycle 2 (note 2) t acs /oe d out t oe t olz t clz t ohz t chz high-z notes: 1. device is continuously selected. /oe, /cs < v il. 2. /we is high for read cycle.
gm76c256cl/ll lg semicon 38 t wc add write cycle 1 (/we controlled) (note 1, 2) t cw /cs /we d in valid data d out high-z t aw t as t wp t wr t dh t dw t ow t whz notes: 1. the internal write time of the memory is defined by the overlap of /cs low and /we low. both signals must be low to initiate a write and either signal can terminate a write by going high. the data input set-up and hold timing should be referenced to the rising edge of the signal that terminates the write. 2. data i/o is high impedance if /oe = v ih .
gm76c256cl/ll lg semicon 39 t wc add write cycle 2 (/cs controlled) (note 1, 2, 3) t cw valid data high-z t aw t wr t dh t dw /cs /we d in d out t as t wp notes: 1. the internal write time of the memory is defined by the overlap of /cs low and /we low. both signals must be low to initiate a write and either signal can terminate a write by going high. the data input set-up and hold timing should be referenced to the rising edge of the signal that terminates the write. 2. data i/o is high impedance if /oe = v ih . 3. if /cs goes high simultaneously with /we high, the output remains in a high impedance state.
gm76c256cl/ll lg semicon note: when retaining data in standby mode, supply voltage can be lowered within a certain range. read or write cycle cannot be performed while the supply voltage is low. symbol parameter unit c in c out input capacitance output capacitance pf pf max 6 8 min test conditions - - *note: this parameter is sampled and not 100% tested. 40 data retention timing notes: 1. typ, values are measured at 25 c t cdr chip select to data retention time ns - - 0 t r operation recovery time ms - - refer to the figure below i ccr data retention current ua - v cc = 3.0v /cs > 2.8v 15 *1 20 1 - *1 data retention characteristics (t a = -25 ~ 85 c ) symbol parameter unit v ccr data retention supply voltage v max 5.5 7 typ - min 0.5 2.0 - - 10 test conditions /cs > v ccr - 0.2v *1 *1 0.5 1 data retention mode gnd t cdr v cc /cs 4.5v 2.2v v ccr t r /cs v ccr - 0.2v > 5 0 to +70 c (ll) -25 to +85 c (lle) -25 to +85 c (le) 0 to +70 c (l) capacitance ( f = 1mh z , t a = 25 c ) v i = 0v v o = 0v
41 package dimensions unit: inches (mm) 0 ~ 15 o typ 0.100(2.54) 0.022(0.559) max 0.015(0.381) min 1.470(37.340) max 1.447(36.754) min 0.050(1.27) min 0.065(1.65) max 0.530(13.462) min 0.550(13.970) max 0.600(15.240) typ 0.190(4.826) max 0.015(0.38) min 0.140(3.556) max 0.120(3.048) min 0.155(3.937) max 0.145(3.683) min 0.015(0.380) max 0.008(0.200) min 28 sop 0.327(8.31) min 0.350(8.89) max 0.020(0.51) max 0.012(0.30) min typ 0.050(1.270) 0.006(0.16) max 0.004(0.10) min 0.012(0.30) max 0.004(0.10) min 0.452(11.48) min 0.500(12.70) max 0.050(1.27) max 0.030(0.76) min 0.106(2.70) max 0.101(2.56) min 0.710(18.03) min 0.762(19.35) max 0 ~ 8 o
gm76c256cl/ll lg semicon 42 unit: inches (mm) 28 tsop-i 0.006(0.15) max 0.002(0.05) min 0.313(8.1) min 0.317(8.3) max 0.022(0.55) 0.006(0.15) min 0.008(0.30) max typ 0.467(11.86) max 0.461(11.70) min #22 #28 #1 #7 #21 #8 0.044(1.0) max 0.035(1.2) min 0.019(0.4) max 0.020(0.6) min 0.528(13.50) max 0.527(13.30) min
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