
32K x 24 Static RAM Module
CYM1720
Cypress Semiconductor Corporation
3901 North First Street
San Jose
CA 95134
408-943-2600
September 1989 – Revised April 1993
1CYM1720
Features
High-density 768-kilobit SRAM module
High-speed CMOS SRAMs
—Access time of 15 ns
56-pin, 0.5-inch-high ZIP package
Low active power
—1.8W (max. for t
AA
= 25 ns)
SMD technology
TTL-compatible inputs and outputs
Commercial temperature range
Small PCB footprint
—0.66 sq. in.
Functional Description
The CYM1720 is a high-performance 768-kilobit static RAM
module organized as 32K words by 24 bits. This module is
constructed using three 32K x 8 static RAMs in SOJ packages
mounted onto an epoxy laminate board with pins.
Writing to the device is accomplished when the chip select
(CS) and write enable (WE) inputs are both LOW. Data on
the input/output pins (I/O
0
through I/O
23
) of the device is
written into the memory location specified on the address
pins (A
0
through A
14
).
Reading the device is accomplished by taking the chip select
(CS) and output enable (OE) LOW while write enable (WE)
remains HIGH. Under these conditions, the contents of the
memory location specified on the address pins will appear
on the input/output pins.
The input/output pins remain in a high-impedance state unless
the module is selected, outputs are enabled, and write enable
is HIGH.
Shaded area contains preliminary information.
Logic Block Diagram
Pin Configuration
1720–1
A
0
A
14
1720–2
OE
WE
CS
I/O
0
I/O
7
I/O
8
I/O
15
ZIP
Top View
OE
A
9
WE
A
8
A
NC
I/O
15
NC
I/O
13
I/O
11
I/O
9
GND
I/O
17
I/O
19
I/O
21
I/O
23
V
CC
I/O
7
GND
A
1
I/O
5
I/O
3
I/O
1
V
CC
I/O
0
CS
NC
I/O
8
A
14
GND
I/O
16
I/O
22
V
CC
A
12
A
10
A
6
A
4
A
2
A
0
32K x 8
SRAM
15
8
32K x 8
SRAM
8
32K x 8
SRAM
8
I/O
16
I/O
23
2
4
6
8
10
12
14
16
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
48
50
52
54
56
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
37
39
41
43
45
47
49
51
53
55
A
11
V
CC
GND
NC
A
3
A
5
A
7
I/O
20
I/O
18
GND
GND
I/O
14
I/O
12
I/O
10
I/O
I/O
4
I/O
2
Selection Guide
1720-15
15
450
120
1720-20
20
450
120
1720-25
25
330
60
1720-30
30
330
60
1720-35
35
330
60
Maximum Access Time (ns)
Maximum Operating Current (mA)
Maximum Standby Current (mA)