MICROCIRCUIT CORPORATION
DESCRIPTION
The Accutek AK632256 SRAM Module consists of eight fast high
performance SRAMs mounted on a low profile, 64 pin SIM or ZIP
Board. The module utilizes four 28 pin 256K x 4 SRAMs in SOJ
packages and four decoupling capacitors mounted on each side of
a printed circuit board.
The SRAMs used have common I/O functions and single output en-
able functions. Also, four separate chip select (CE) connections are
used to independently enable the four bytes. The modules can be
supplied in a variety of access time values from 12 nSEC to
45 nSEC in CMOS or BiCMOS technology.
1
ACCUTEK
AK632256W / AK632256Z
262,144 x 32 Bit CMOS/BiCMOS
Static Random Access Memory
Front View
64-Pin SIM
+
+
1
32
33
64
64-Pin ZIP
32
33
64
The Accutek module is designed to have a maximum seated height
of 0.680 inch SIM or 0.540 inch ZIP to provide for the lowest height
off the board. By offset-mounting the back surface SRAMs on the
SIM version, the module can be mounted in either angled or
straight-up SIM sockets. Each conforms to JEDEC standard sizes
and pin-out configurations. Using two pins for module memory den-
sity identification, PD
0
and PD
1
, minimizes interchangeability and
design considerations when changing from one module size to an-
other in customer applications.
FEATURES
·
262,144 x 32 bit organization
·
JEDEC Standardized 64 pin SIM or ZIP format
·
Common I/O, single OE functions with four separate chip
selects (CE)
·
Low height, 0.680 inch SIM or 0.540 inch ZIP maximum
·
Upward compatible with 512K x 32 (AK532512) and
1 Meg x 32 (AK6321024)
·
Downward compatible with 32K x 32 (AK63232), 64K x 32
(AK63264) and 128K x 32 (AK632128)
·
Presence Detect PD
0
and PD
1
for identifying module density
·
Fast access times range from 12 nSEC BiCMOS to 45 nSEC
CMOS
·
TTL-compatible inputs and outputs
·
Single 5 volt power supply - AK632256W, AK632256Z
·
Single 3.3 volt power supply - AK632256W/3.3,
AK632256Z/3.3
·
Operating temperature range in free air, 0
0
C to 70
0
C
ELECTRICAL SPECIFICATIONS
Timing diagrams and basic electrical characteristics are those of
the standard 256K x 4 SRAMs used to construct these modules.
Accutek’s module design allows the flexibility of selecting indus-
try-compatible 256K x 4 SRAMs from several semiconductor manu-
facturers.
PIN NOMENCLATURE
A
0
- A
17
CE
1
- CE
4
DQ
1
- DQ
32
OE
PD
0
- PD
1
Vcc
Vss
WE
Address Inputs
Chip Enable
Data In/Data Out
Output Enable
Presence Detect
Power Supply
Ground
Write Enable
PIN ASSIGNMENT
PIN #
SYMBOL
PIN #
SYMBOL
PIN #
SYMBOL
PIN #
SYMBOL
FUNCTIONAL DIAGRAM
CE
4
CE
3
A
17
A
16
OE
Vss
DQ
25
DQ
17
DQ
26
DQ
18
DQ
27
DQ
19
DQ
28
DQ
20
A
3
A
10
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
A
4
A
11
A
5
A
12
Vcc
A
13
A
6
DQ
21
DQ
29
DQ
22
DQ
30
DQ
23
DQ
31
DQ
24
DQ
32
Vss
1
2
3
4
5
6
7
8
9
10
11
Vss
PD
0
PD
1
DQ
1
DQ
9
DQ
2
DQ
10
DQ
3
DQ
11
DQ
4
DQ
12
Vcc
A
0
A
7
A
1
A
8
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
A
2
A
9
DQ
13
DQ
5
DQ
14
DQ
6
DQ
15
DQ
7
DQ
16
DQ
8
Vss
WE
A
15
A
14
CE
2
CE
1
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
MODULE OPTIONS
Leadless SIM: AK632256W
Leaded SIP: AK632256G
Leaded ZIP: AK632256Z
12
13
14
15
16
PD
0
= Vss
PD
1
= Vss
ACCUTEK [ ACCUTEK MICROCIRCUIT CORPORATION ]
