2K x 8 Static RAM
CY7C128A
Cypress Semiconductor Corporation
•
3901 North First Street
•
San Jose
•
CA 95134
•
408-943-2600
December 1988 – Revised December 1992
1CY 7C12 8A
Features
• Automatic power-down when deselected
• CMOS for optimum speed/power
• High speed
—15 ns
• Low active power
— 440 mW (commercial)
— 550 mW (military)
• Low standby power
— 110 mW
• TTL-compatible inputs and outputs
• Capable of withstanding greater than 2001V electro-
static discharge
•VIH of 2.2V
Functional Description
The CY7C128A is a high-performance CMOS static RAM or-
ganized as 2048 words by 8 bits. Easy memory expansion is
provided by an active LOW chip enable (CE), and active LOW
output enable (OE) and three-state drivers. The CY7C128A
has an automatic power-down feature, reducing the power
consumption by 83% when deselected.
Writing to the device is accomplished when the chip enable
(CE) and write enable (WE) inputs are both LOW.
Data on the eight I/O pins (I/O0 through I/O7) is written into the
memory location specified on the address pins (A0 through
A10).
Reading the device is accomplished by taking chip enable
(CE) 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 eight I/O pins.
The I/O pins remain in high-impedance state when chip enable
(CE) or output enable (OE) is HIGH or write enable (WE) is LOW.
The CY7C128A utilizes a die coat to insure alpha immunity.
Logic Block Diagram
Pin Configurations
C128A–1
A1
A2
A4
A5
A6
COLUMN
DECODER
INPUT BUFFER
POWER
DOWN
WE
OE
I/O0
CE
I/O1
I/O2
I/O3
Top View
LCC
1
2
3
4
5
6
7
8
9
10
11
14
15
16
20
19
18
17
21
24
23
22
Top View
DIP/SOJ
12
13
A6
A5
A4
A3
WE
VCC
A8
A9
A10
I/O5
I/O4
I/O3
C128A–2
A7
I/O0
I/O1
CE
OE
128 x 16 x 8
ARRAY
I/O7
I/O6
I/O5
I/O4
7C128A
A0
C128A–3
A3
A7
A8
A9
A10
24
4
5
6
7
8
9
10
32 1
23
11 12 13 14 15
22
21
20
19
18
17
16
7C128A
A4
A3
A2
A1
WE
CE
A0
A9
I/O2
GND
I/O7
I/O6
A2
A1
A0
OE
A10
I/O7
I/O6
I/O0
I/O1
Selection Guide
7C128A–15
7C128A–20
7C128A–25
7C128A–35
7C128A–45
Maximum Access Time (ns)
15
20
25
35
45
Maximum Operating
Current (mA)
Commercial
120
100
100
100
Military
125
125
100
100
Maximum Standby
Current (mA)
Commercial
40/40
40/20
20
20
Military
40/20
40
20
20