ACCUTEK AK58256AS

Accutek
Microcircuit
Corporation
AK58256AG / AK58256AS
262,144 x 8 bit CMOS
Dynamic Random Access Memory
DESCRIPTION
Front View
The Accutek AK58256AG/AS high density memory module is a
random access memory organized in 256K x 8 bit words. The
assembly consists of two 256K x 4 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 density increase over standard DIP packaging.
30-Pin SIM
+
+
30
1
30-Pin SIP
The operation of the AK58256 is identical to two 256K x 4
DRAMs. The data input/output is 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 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 x 8 bit organization
· Optional 30 Pad leadless SIM (Single In-Line Module) or 30
Pin leaded SIP (Single In-Line Package)
· JEDEC standard pinout
· Common CAS, RAS and WE control for eight DQ lines
· Separate CAS control for one separate pair of D and Q lines
· 1024 refresh cycles/16ms, A0 to A8
· Power:
.99 Watt Max Active (60 nS)
.88 Watt Max Active (70 nS)
.77 Watt Max Active (80 nS)
.65 Watt Max Active (100 nS)
11 mWatt standby (max)
· Operating free air temperature: 00 to 700C
· Upward compatible with AK581024, AK584096 and
AK5816384
· Functionally and Pin compatible with AK48256
· Available with access times of 60 to 100 nS
PIN NOMENCLATURE
PIN ASSIGNMENT
FUNCTIONAL DIAGRAM
PIN #
SYMBOL
PIN #
SYMBOL
1
Vcc
16
DQ5
Address Inputs
2
CAS
17
A8
CAS
Column Address Strobe
3
DQ1
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
8
A3
23
DQ7
9
Vss
24
NC
NC
No Connect
10
DQ3
25
DQ8
11
A4
26
NC
MODULE OPTIONS
12
A5
27
RAS
13
DQ4
28
NC
Leadless SIM: AK58256AS
14
A6
29
NC
15
A7
30
Vcc
DQ1 - DQ8
Data In / Data Out
A0 - A8
Leaded SIP: AK58256AG
A0 - A8 +
RAS +
CAS +
WE +
DQ1 +
DQ2 +
DQ3 +
DQ4 +
A0 - A8
* RAS
* CAS
* WE
* DQ1
* DQ2
* DQ3
* DQ4
OE
*
+
+
+
+
A0 - A8
* RAS
* CAS
* WE
* DQ1
* DQ2
* DQ3
* DQ4
OE
*
DQ5
DQ6
DQ7
DQ8
EXAMPLES:
ORDERING INFORMATION
AK58256ASP-60
PART NUMBER CODING INTERPRETATION
Position
1
2
3
4
5
6
7
8
AK58256AGK-70
256K x 8, Dynamic RAM, Leaded SIP, Static Column Mode
Commercial, 70 nSEC AccessTime
MECHANICAL DIMENSIONS
Inches
0.410
0.390
1
+
0.100
T.P.
3.510
3.490
3.245
3.225
3.110
3.090
30
+
+
0.100
TYP
The numbers and coding on this page do not include all variations
available, but are shown as examples of the most widely used variations. Contact Accutek if other information is required.
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:
sales@accutekmicro.com
Internet: www.accutekmicro.com
0.260
0.240
0.085
0.075
0.325
0.275
+
1
0.024
0.016
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
60 = 60 nS
8 = 8 nS
70 = 70 nS
12 = 12 nS
80 = 80 nS
15 = 15 nS
10 = 100 nS 20 = 20 nS
12 = 120 nS 70 = 70 nS
15 = 150 nS 85 = 85 nS
256K x 8, Dynamic RAM, Leadless SIM, Page Mode, Commercial,
60 nSEC Access Time
0.100
T.P.
8
4
0.505
0.495
7
3
0.100
TYP
6
2
0.515
0.505
5
1
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.