Integrated Silicon Solution, Inc. 1-800-379-47741 SR020-1O 05/24/99ISSI reserves the right to make changes to its products at any time without notice in order to improve design and supply the best possible product. We assume no responsibility for any errors which may appear in this publication. Copyright 1999, Integrated Silicon Solution, Inc.FEATURES High-speed access time: 10, 12, 15, 20, 25 ns Low active power: 400 mW (typical) Low standby power 250 W (typical) CMOS standby 55 mW (typical) TTL standby Fully static operation: no clock or refresh required TTL compatible inputs and outputs Single 5V power supplyDESCRIPTION The ISSI IS61C256AH is a very high-speed, low power, 32,768 word by 8-bit static RAMs. They are fabricated using ISSIs high-performance CMOS technology. This highly reli- able process coupled with innovative circuit design tech- niques, yields access times as fast as 10 ns maximum.When CE is HIGH (deselected), the device assumes a standby mode at which the power dissipation can be reduced down to 250 W (typical) with CMOS input levels.Easy memory expansion is provided by using an active LOW Chip Enable (CE) input and an active LOW Output Enable (OE) input. The active LOW Write Enable (WE) controls both writing and reading of the memory.The IS61C256AH is pin compatible with other 32K x 8 SRAMs and are available in 28-pin PDIP, SOJ, and TSOP (Type I) packages.IS61C256AH 32K x 8 HIGH-SPEED CMOS STATIC RAMMAY 1999FUNCTIONAL BLOCK DIAGRAMA0-A14CEOEWE32K X 8 MEMORY ARRAYDECODERCOLUMN I/OCONTROL CIRCUITGNDVCCI/O DATA CIRCUITI/O0-I/O7ISSI 2Integrated Silicon Solution, Inc. 1-800-379-4774 SR020-1O 05/24/99IS61C256AHISSI 12345678910111213142827262524232221201918171615A14A12A7A6A5A4A3A2A1A0I/O0I/O1I/O2GNDVCCWEA13A8A9A11OEA10CEI/O7I/O6I/O5I/O4I/O3PIN CONFIGURATION 28-Pin DIP and SOJPIN CONFIGURATION 28-Pin TSOPPIN DESCRIPTIONSA0-A14Address InputsCEChip Enable InputOEOutput Enable InputWEWrite Enable InputI/O0-I/O7Bidirectional PortsVccPowerGNDGroundABSOLUTE MAXIMUM RATINGS(1)SymbolParameterValueUnit VTERMTerminal Voltage with Respect to GND0.5 to +7.0V TBIASTemperature Under Bias55 to +125C TSTGStorage Temperature65 to +150C PTPower Dissipation1.5W IOUTDC Output Current (LOW)20mANote: 1. Stress greater than those listed under ABSOLUTE 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 specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect reliability.22 23 24 25 26 27 28 1 2 3 4 5 6 721 20 19 18 17 16 15 14 13 12 11 10 9 8OE A11 A9 A8 A13 WE VCC A14 A12 A7 A6 A5 A4 A3A10 CE I/O7 I/O6 I/O5 I/O4 I/O3 GND I/O2 I/O1 I/O0 A0 A1 A2TRUTH TABLEModeWEWEWEWEWECECECECECEOEOEOEOEOEI/O OperationVcc CurrentNot SelectedXHXHigh-ZISB1, ISB2 (Power-down) Output Disabled HLHHigh-ZICC ReadHLLDOUTICC WriteLLXDINICCIntegrated Silicon Solution, Inc. 1-800-379-47743 SR020-1O 05/24/99IS61C256AHISSI POWER SUPPLY CHARACTERISTICS(1) (Over Operating Range)-10 -12 -15 -20 -25 SymbolParameterTest ConditionsMin. Max.Min. Max.Min. Max.Min. Max.Min. Max.UnitICCVcc Dynamic OperatingVCC = Max., CE = VILCom.165155145135125mA Supply CurrentIOUT = 0 mA, f = fMAXInd.165155145135ISB1TTL Standby CurrentVCC = Max.,Com.2525252525mA (TTL Inputs)VIN = VIH or VILInd.30303030 CE VIH, f = 0ISB2CMOS StandbyVCC = Max.,Com.22222mA Current (CMOS Inputs)CE VCC 0.2V,Ind.10101010 VIN VCC 0.2V, or VIN 0.2V, f = 0Note: 1. At f = fMAX, address and data inputs are cycling at the maximum frequency, f = 0 means no input lines change.OPERATING RANGERangeAmbient TemperatureSpeedVCC Commercial0C to +70C-10, -125V 5% -15, -20, -255V 10% Industrial40C to +85C-125V 5% -15, -20, -255V 10%DC ELECTRICAL CHARACTERISTICS (Over Operating Range)SymbolParameterTest ConditionsMin.Max.UnitVOHOutput HIGH VoltageVCC = Min., IOH = 4.0 mA2.4VVOLOutput LOW VoltageVCC = Min., IOL = 8.0 mA0.4VVIHInput HIGH Voltage2.2VCC + 0.5VVILInput LOW Voltage(1)0.50.8VILIInput LeakageGND VIN VCCCom.55A Ind.1010ILOOutput LeakageGND VOUT VCC,Com.55A Outputs DisabledInd.1010Note: 1. VIL = 3.0V for pulse width less than 10 ns.CAPACITANCE(1,2)SymbolParameterConditionsMax.UnitCINInput CapacitanceVIN = 0V8pFCOUTOutput CapacitanceVOUT = 0V10pFNotes: 1. Tested initially and after any design or process changes that may affect these parameters. 2. Test conditions: TA = 25C, f = 1 MHz, Vcc = 5.0V.4Integrated Silicon Solution, Inc. 1-800-379-4774 SR020-1O 05/24/99IS61C256AHISSI READ CYCLE SWITCHING CHARACTERISTICS(1) (Over Operating Range)-10 -12 -15-20-25 SymbolParameterMin.MaxMin.Max.Min.Max.Min.Max.Min.Max.UnittRCRead Cycle Time1012152025nstAAAddress Access Time1012152025nstOHAOutput Hold Time22222nstACECE Access