DESCRIPTION Accutek Microcircuit Corporation AK48256S / AK48256G 262,144 X 8 Bit MOS Dynamic Random Access Memory Front View The Accutek AK48256 high density memory modules is a random access memory organized in 256K x 8 bit words. The assembly consists of eight standard 256K x 1 DRAMs in plastic leaded chip carriers (PLCC) mounted on the front side of a printed circuit board. The module can be configured as a leadless 30 pad SIM or a leaded 30 pin SIP. This packaging approach provides a 6 to 1 density increase over standard DIP packaging. 30-Pin SIM 30 1 30-Pin SIP The operation of the AK48256 is identical to eight 256K x 1 DRAMs. The data input is tied to the data output and brought out separately for each device, with common RAS, CAS and WE control. This common I/O feature dictates the use of early-write cycles to prevent contention of D and Q. Since the Write-Enable (WE) signal must always go low before CAS in a write cycle, Read-Write and Read-Modify-Write operation is not possible. 1 FEATURES * 262,144 by 8 bit organization * Optional 30 Pad leadless SIM (Single In-Line Module) or 30 Pin leaded SIP (Single In-Line Package) * JEDEC standard pinout * Each device has common D and Q lines with common RAS, CAS and WE control * 2.8 Watt active and 180 mW standby (max) * Operating free air temperature 00C to 700C * Upward compatible with AK481024, AK581024, AK584096 and AK5816384 * Functionally and Pin compatible with AK58256A PIN NOMENCLATURE PIN ASSIGNMENT FUNCTIONAL DIAGRAM A0 - A8 Address Inputs PIN # SYMBOL PIN # SYMBOL 1 Vcc 16 DQ5 DQ1 - DQ8 Data In / Data Out 2 CAS 17 A8 CAS Column Address Strobe 3 DQ! 18 NC RAS Row Address Strobe 4 A0 19 NC 5 A1 20 DQ6 WE Write Enable 6 DQ2 21 WE Vcc 5v Supply 7 A2 22 Vss Vss Ground DQ7 NC No Connect 8 A3 23 9 Vss 24 NC 10 DQ3 25 DQ8 11 A4 26 NC MODULE OPTIONS 12 A5 27 RAS 13 DQ4 28 NC Leadless SIM: AK48256S 14 A6 29 NC 15 A7 30 Vcc Leaded SIP: AK48256G MECHANICAL DIMENSIONS ORDERING INFORMATION PART NUMBER CODING INTERPRETATION Position 1 2 3 6 Inches 7 8 0.425 0.375 .100 .060 0.325 0.275 1 1 0.100 T.P. 3.525 3.475 3.100 3.090 30 0.100 TYP 0.200" MAX 0.053 0.047 Product AK = Accutek Memory Type 4 = Dynamic RAM 5 = CMOS Dynamic RAM 6 = Static RAM Organization/Word Width 1 = by 1 16 = by 16 4 = by 4 32 = by 32 8 = by 8 36 = by 36 9 = by 9 Size/Bits Depth 64 = 64K 4096 = 4 MEG 256 = 256K 8192 = 8 MEG 1024 = 1 MEG 16384 = 16 MEG Package Type G = Single In-Line Package (SIP) S = Single In-Line Module (SIM) D = Dual In-Line Package (DIP) W = .050 inch Pitch Edge Connect Z = Zig-Zag In-Line Package (ZIP) Special Designation P = Page Mode N = Nibble Mode K = Static Column Mode W = Write Per Bit Mode V = Video Ram Separator - = Commercial 00C to +700C M = Military Equivalent Screened (-550C to +1250C) I = Industrial Temperature Tested (-450C to +850C) X = Burned In Speed (first two significant digits) DRAMS SRAMS 50 = 50 nS 8 = 8 nS 60 = 60 nS 10 = 10 nS 70 = 70 nS 12 = 12 nS 80 = 80 nS 15 = 15 nS 0.024 0.016 8 5 0.685 0.635 7 4 0.100 TYP 6 3 0.100 TYP 5 2 0.685 0.635 4 1 The numbers and coding on this page do not include all variations available but are show as examples of the most widely used variations. Contact Accutek if other information is required. EXAMPLES: AK48256SP-10 256K x 8, 100 nSEC DRAM 30 pin SIM Configuration, Page Mode AK48256GK-80 256K x 8, 80 nSEC DRAM 30 pin SIP Configuration, Static Column Mode ACCUTEK MICROCIRCUIT CORPORATION BUSINESS CENTER at NEWBURYPORT 2 NEW PASTURE ROAD, SUITE 1 NEWBURYPORT, MA 01950-4054 VOICE: 978-465-6200 FAX: 978-462-3396 Email: accutek@seacoast.com Internet: www.accutekmicro.com Accutek Reserves the right to make changes in specifications at any time and without notice. Accutek does not assume any responsibility for the use of any circuitry described; no circuit patent licenses are implied. Preliminary data sheets contain minimum and maximum limits based upon design objectives, which are subject to change upon full characterization over the specific operating conditions.