DESCRIPTION
Accutek
Microcircuit
Corporation
+
1
AK59256AS / AK59256AG
262,144 Word by 9 bit, CMOS
Dynamic Random Access Memory
Front View
30-Pin SIM
+
30
The Accutek AK59256A high density memory modules is a random
access memory organized in 256K x 9 bit words. The assembly
consists of two 256K x 4 and one 256K x 1 DRAMs in surface mount
packages mounted to 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 better than 6 to 1 den-
sity increase over standard DIP packaging.
The operation of the AK59256A is identical to two 256K x 4 DRAMs
plus one 256K x 1 DRAM. For the lower eight bits data input is tied
to data output and brought out separately for each 256K x 4 device,
with common RAS, CAS and WE control. The OE pins are tied to
Vss which dictates the use of early-write cycles to prevent conten-
tion 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. For the ninth bit, the data input (D
9)
and
data output (Q
9
) pins are brought out separately and controlled by a
separate PCAS for that bit. Bit nine is generally used for parity.
30-Pin SIP
+
1
+
FEATURES
·
262,144 x 9 bit organization
·
Optional 30 Pad SIM (Single In-Line Module) or 30 Pin leaded
SIP (Single In-Line Package)
·
JEDEC standard pinout
·
Common CAS, RAS and WE control for the lower eight bits
·
Separate PCAS control for D
9
and Q
9
·
Power:
1.26 Watt Max Active (70 nSEC)
1.10 Watt Max Active (80 nSEC)
.935 Wat Max Active (100 nSEC)
22 mWatt Standby (Max)
·
Operating free air temperature: 0
o
to 70
o
C
·
Upward compatible with AK491024, AK591024, AK594096
and AK5916384
·
Functionally and Pin compatible with AK49256
·
Available with access times of 60 nSEC to 100 nSEC
PIN NOMENCLATURE
DQ
1
- DQ
8
D
9
Q
9
A
0
- A
9
CAS, PCAS
RAS
WE
Vcc
Vss
NC
Data In / Data Out
Data In
Data Out
Address Inputs
Column Address Strobe
Row Address Strobe
Write Enable
5v Supply
Ground
No Connect
PIN ASSIGNMENT
PIN #
SYMBOL
PIN #
SYMBOL
FUNCTIONAL DIAGRAM
DQ5
A8
NC
NC
DQ6
WE
Vss
DQ7
NC
DQ8
Q9
RAS
PCAS
D9
Vcc
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Vcc
CAS
DQ1
A0
A1
DQ2
A2
A3
Vss
DQ3
A4
A5
DQ4
A6
A7
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
A0 - A8 +
RAS +
CAS +
WE +
DQ1 +
DQ2 +
DQ3 +
DQ4 +
A0 - A8
* RAS
* CAS
* WE
* DQ1
* DQ2
* DQ3
* DQ4
OE
*
DQ5
DQ6
DQ7
DQ8
+
+
+
+
A0 - A8
* RAS
* CAS
* WE
* DQ1
* DQ2
* DQ3
* DQ4
OE
*
MODULE OPTIONS
Leadless SIM: AK59256AS
Leaded SIP: AK59256AG
PCAS +
A0 - A8
* RAS
* CAS
* WE
D9 +
Q9 +
*D
Q *
Position
1
2
ORDERING INFORMATION
PART NUMBER CODING INTERPRETATION
1
2
3
4
5
6
7
8
MECHANICAL DIMENSIONS
Inches
3
4
5
6
7
8
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 0
0
C to +70
0
C
M = Military Equivalent Screened
(-55
0
C to +125
0
C)
I = Industrial Temperature Tested
(-45
0
C to +85
0
C)
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
0.515
0.505
0.410
0.390
0.260
0.240
0.085
0.075
0.100
TYP
0.100
T.P.
0.024
0.016
0.505
0.495
0.325
0.275
+
0.100
T.P.
3.110
3.090
+
1
1
3.245
3.225
3.510
3.490
+
0.200"
MAX
0.053
0.047
+
0.100
TYP
30
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:
AK59256AGP-60
256K x 9, 60 nSEC, DRAM, SIP Configuration, 30 Pin, Page Mode
AK59256ASP-70
256K x 9, 70 nSEC, DRAM, SIM Configuration, 30 Pin, Page 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 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.
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