AK58256AG_09 Datasheet, PDF (1/2 Pages) ACCUTEK MICROCIRCUIT CORPORATION – Dynamic Random Access Memory

ACCUTEK
DESCRIPTION
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.
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.
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
AK58256AG / AK58256AS
262,144 x 8 bit CMOS
Dynamic Random Access Memory
Front View
30-Pin SIM
+
+
1
30
30-Pin SIP
+
+
1
· 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
DQ1 - DQ8
A0 - A8
Data In / Data Out
Address Inputs
PIN #
1
2
SYMBOL
Vcc
CAS
PIN #
16
17
CAS
RAS
WE
Column Address Strobe ³
4
Row Address Strobe
5
Write Enable
6
DQ1
18
A0
19
A1
20
DQ2
21
Vcc
5v Supply
Vss
Ground
NC
No Connect
7
A2
22
8
A3
23
9
Vss
24
10
DQ3
25
11
A4
26
MODULE OPTIONS
12
A5
27
13
DQ4
28
Leadless SIM: AK58256AS
Leaded SIP: AK58256AG
14
A6
29
15
A7
30
SYMBOL
DQ5
A8
NC
NC
DQ6
WE
Vss
DQ7
NC
DQ8
NC
RAS
NC
NC
Vcc
FUNCTIONAL DIAGRAM
A0 - A8 ₊
RAS ₊
CAS ₊
WE +
DQ1 +
DQ2 +
DQ3 +
DQ4 +
DQ5 +
DQ6 +
DQ7 +
DQ8 +
A0 - A8
RAS
CAS
WE
* ^DQ1
* ^DQ2
* ^DQ3
* ^DQ4
OE *
A0 - A8
RAS
CAS
WE
* ^DQ1
* ^DQ2
* ^DQ3
* ^DQ4
OE _*