1 - Al Kossow's Bitsavers

MOSLSITMS4256. TMS4257262.144·8IT DYNAMIC RANDOM·ACCESS MEMORIESMAY 1983 - REVISED JANUARY 1984• 262,144 X 1 Organization• Single +5-V Supply (10% Tolerance)• JEDEC Standardized Pin Out• Upward Pin Compatible with TMS4164(64K Dynamic RAM)• Performance Ranges:ACCESS ACCESSTIME TIMEDEVICE ROW COLUMNADDRESS ADDRESS(MAX) (MAX)TMS4256-10TMS4257-10TMS4256-12TMS4257-12TMS4256-15TMS4257-15TMS4256-20TMS4257"20100 ns 50 ns120 ns 60 ns150 ns 75 ns200 ns 100 ns• Long Refresh Period ... 4 ms (MAX)READORWRITECYCLE(MIN)200 ns230 ns260 ns330 nsTMS4256. TMS4257 ... JL OR NL PACKAGEAD-ASASDWRASAD• Low Refresh Overhead Time ... As Low As 1.3% of Total Refresh Period• On-Chip Substrate Bias Generator• All Inputs, Outputs, arid Clocks Fully TTL Compatible• 3-State Unlatched Output• Common I/O Capability with "Early Write" Feature• Page ('4256) or Nibble-Mode ('4257) Options for Faster Access Operation• Power Dissipation As Low As:Operating ... 225 mW (TVP)Standby ... 12.5 mW (TVP)• RAS-Only Refresh Mode• Hidden Refresh Mode• CAS-Before-RAS Refresh Mode (Optional)CASDQRASINVDDVSSA2AlVDD(TOP VIEW)VSSCASQA6A3A4A5A7, PIN NOMENCLATUREAddress InputsColumn Address StrobeData-InData-OutRow Address StrobeWrite Enable+5-V SupplyGround• Available with MIL-STD-883B Processing and L(OOC to 70°C), E(-400C to 85°CI, or S(-55°C to100°C) Temperature Ranges in the Future........oc.c.::::sen>- ...oEQ)~"Ct:CO~«ex:(.)'ECOt:>-CdescriptionThe' 4256 and' 4257 are high-speed, 262, 144-bit dynamic random-access memories, organized as 262,144 wordsofone bit each. They employ state-of-the-art SMOS (scaled MOS) N-channel double-level polysilicon gate technologyfor very high performance combined with low cost and improved reliability.These devices feature maximum RAS access times of 100 ns, 120 ns, 150 ns, or 200 ns. Typical power dissipationis as low as 225 mW operating and 12.5 mW standby.New SMOS technology permits operation from a single + 5-V supply, reducing system power supply and decouplingPRODUCT PREVIEWThis document contains information on a product underdevelopment. Texas Instruments reserves the right tochange or discontinue this product without notice.TEXASINSTRUMENTSPOST OFFICE BOX 225012 • DALLAS, TEXAS 75265Copyright © 1984 by Texas Instruments Incorporated4-63