71256S CMOS Static RAM 71256L 256K (32K x 8-Bit) Features Description High-speed address/chip select time The IDT 71256 is a 262,144-bit high-speed static RAM organized as Commercial: 20/25/35ns (max.) 32K x 8. It is fabricated using high-performance, high-reliability CMOS Industrial: 20/25/35ns (max.) technology. Military: 25/35/45/55/70/85/100ns (max.) Address access times as fast as 20ns are available with power Low-power operation consumption of only 350mW (typ.). The circuit also offers a reduced power Battery Backup operation 2V data retention standby mode. When CS goes HIGH, the circuit will automatically go to and Produced with advanced high-performance CMOS remain in, a low-power standby mode as long as CS remains HIGH. This technology capability provides significant system level power and cooling savings. Input and output directly TTL-compatible The low-power (L) version also offers a battery backup data retention Available in standard 28-pin (300 or 600 mil) ceramic DIP, capability where the circuit typically consumes only 5W when operating 28-pin (300 mil) SOJ off a 2V battery. Military product compliant to MIL-STD-883, Class B The IDT71256 is packaged in a 28-pin (300 or 600 mil) ceramic DIP, Industrial temperature range (40C to +85C) is available a 28-pin 300 mil SOJ providing high board level packing densities. for selected speeds The IDT71256 military RAM is manufactured in compliance with the Green parts available, see ordering information latest revision of MIL-STD-883, Class B, making it ideally suited to military temperature applications demanding the highest level of performance and reliability. Functional Block Diagram A0 VCC GND 262,144 BIT ADDRESS MEMORY ARRAY DECODER A14 I/O0 I/O CONTROL INPUT DATA CIRCUIT I/O7 , CS CONTROL OE CIRCUIT 2946 drw 01 WE 1 Aug.06.2071256S/L CMOS Static RAM 256K (32K x 8-Bit) Military, Commercial, and Industrial Temperature Ranges (1) (1) Pin Configurations Truth Table WE CS OE I/O Function 1 VCC A14 28 XH X High-Z Standby (ISB) 2 A12 27 WE 3 A7 26 A13 XVHC X High-Z Standby (ISB1) A6 4 25 A8 H L H High-Z Output Disabled 71256S/L 5 24 A5 A9 A4 6 SD28 23 A11 HL L DOUT Read Data CD28 7 22 A3 OE LL X DIN Write Data PJG28 A2 8 21 A10 9 20 2946 tbl 02 A1 CS NOTE: A0 10 19 I/O7 1. H = VIH, L = VIL, X = Don t care. 11 18 I/O0 I/O6 I/O1 12 17 I/O5 13 I/O2 16 I/O4 14 GND 15 I/O3 (1) 2946 drw 02 Absolute Maximum Ratings Symbol Rating Com l. Ind. Mil. Unit DIP/SOJ VTERM Terminal Voltage -0.5 to +7.0 -0.5 to +7.0 -0.5 to +7.0 V Top View with Respect to GND NOTE: 1. This text does not indicate orientation of actual part-marking. o TA Operating 0 to +70 -40 to +85 -55 to +125 C Temperature o TBIAS Temperature -55 to +125 -55 to +125 -65 to +135 C Under Bias Pin Descriptions Storage o TSTG -55 to +125 -55 to +125 -65 to +150 C Name Description Temperature A0 - A14 Address Inputs Power PT 1.0 1.0 1.0 W Dissipation I/O0 - I/O7 Data Input/Output IOUT DC Output Current 50 50 50 mA Chip Select CS 2946 tbl 03 NOTE: WE Write Enable 1. Stresses greater than those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent damage to the device. This is a stress rating only and OE Output Enable 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 GND Ground to absolute maximum rating conditions for extended periods may affect reliability. VCC Power 2946 tbl 01 Capacitance (TA = +25C, f = 1.0MHz) (1) Symbol Parameter Conditions Max. Unit CIN Input Capacitance VIN = 0V 11 pF CI/O I/O Capacitance VOUT = 0V 11 pF 2946 tbl 04 NOTE: 1. This parameter is determined by device characterization, but is not production tested. 2 Aug.06.20