DESCRIPTION
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 in-
crease over standard DIP packaging.
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 al-
ways go low before CAS in a write cycle, Read-Write and
Read-Modify-Write operation is not possible.
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 00Cto70
0C
·Upward compatible with AK481024, AK581024, AK584096 and
AK5816384
·Functionally and Pin compatible with AK58256A
Accutek
Microcircuit
Corporation
AK48256S / AK48256G
262,144 X 8 Bit MOS
Dynamic Random Access Memory
130
1
Front View
30-Pin SIM
30-Pin SIP
PIN NOMENCLATURE
A0-A
8Address Inputs
DQ1-DQ
8Data In / Data Out
CAS Column Address Strobe
RAS Row Address Strobe
WE Write Enable
Vcc 5v Supply
Vss Ground
NC No Connect
MODULE OPTIONS
Leadless SIM: AK48256S
Leaded SIP: AK48256G
PIN ASSIGNMENT
PIN # SYMBOL PIN # SYMBOL
1 Vcc 16 DQ5
2 CAS 17 A8
3 DQ! 18 NC
4A019NC
5 A1 20 DQ6
6 DQ2 21 WE
7 A2 22 Vss
8 A3 23 DQ7
9 Vss 24 NC
10 DQ3 25 DQ8
11 A4 26 NC
12 A5 27 RAS
13 DQ4 28 NC
14 A6 29 NC
15 A7 30 Vcc
FUNCTIONAL DIAGRAM
ORDERING INFORMATION
PART NUMBER CODING INTERPRETATION
Position 12345678
1 Product
AK = Accutek Memory
2 Type
4 = Dynamic RAM
5 = CMOS Dynamic RAM
6 = Static RAM
3 Organization/Word Width
1 = by 1 16 = by 16
4 = by 4 32 = by 32
8 = by 8 36 = by 36
9 = by 9
4 Size/Bits Depth
64 = 64K 4096 = 4 MEG
256 = 256K 8192 = 8 MEG
1024 = 1 MEG 16384 = 16 MEG
5 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)
6 Special Designation
P = Page Mode
N = Nibble Mode
K = Static Column Mode
W = Write Per Bit Mode
V = Video Ram
7 Separator
- = Commercial 00Cto+70
0C
M = Military Equivalent Screened
(-550C to +1250C)
I = Industrial Temperature Tested
(-450Cto+85
0C)
X = Burned In
8 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
130
3.525
3.475
0.100
TYP
0.325
0.275
0.100
T.P.
3.100
3.090
0.024
0.016
0.425
0.375
.100
.060
0.685
0.635
1
0.685
0.635
0.100
TYP
0.100
TYP
0.200"
MAX
0.053
0.047
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 im-
plied. 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.
MECHANICAL DIMENSIONS
Inches
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
