Accutek
Microcircuit
Corporation
AK48256S / AK48256G
262,144 X 8 Bit MOS
Dynamic Random Access Memory
DESCRIPTION
Front View
30-Pin SIM
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.
1
30
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 al-
ways 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
PIN #
1
SYMBOL
Vcc
CAS
DQ!
A0
PIN #
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
SYMBOL
A0 - A8
DQ1 - DQ8
CAS
Address Inputs
DQ5
A8
Data In / Data Out
Column Address Strobe
Row Address Strobe
Write Enable
2
3
NC
4
NC
RAS
5
A1
DQ6
WE
Vss
DQ7
NC
WE
6
DQ2
A2
7
Vcc
5v Supply
8
A3
Vss
Ground
9
Vss
DQ3
A4
NC
No Connect
10
11
12
13
14
15
DQ8
NC
A5
RAS
NC
MODULE OPTIONS
DQ4
A6
NC
Leadless SIM: AK48256S
Leaded SIP: AK48256G
A7
Vcc