CY7C197D Datasheet, PDF (1/8 Pages) Cypress Semiconductor – 256K (256K x 1) Static RAM

PRELIMINARY
CY7C197D
256K (256K x 1) Static RAM
Features
• Pin- and function-compatible with CY7C197B
• High speed
— t_AA = 10 ns
• CMOS for optimum speed/power
• Low active power
— I_CC = 60 mA @ 10 ns
• Low CMOS standby power
— I_SB2 = 3 mA
• TTL-compatible inputs and outputs
• Data retention at 2.0V
• Automatic power-down when deselected
• Available in Pb-Free Packages
Functional Description^[1]
The CY7C197D is a high-performance CMOS static RAM
organized as 256K words by 1 bit. Easy memory expansion is
provided by an active LOW Chip Enable (CE) and three-state
drivers. The CY7C197D has an automatic power-down
feature, reducing the power consumption when deselected.
Writing to the device is accomplished when the Chip Enable
(CE) and Write Enable (WE) inputs are both LOW. Data on the
input pin (D_IN) is written into the memory location specified on
the address pins (A₀ through A₁₇).
Reading the device is accomplished by taking chip enable
(CE) 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 data output (D_OUT) pin.
The output pin stays in a high-impedance state when Chip
Enable (CE) is HIGH or Write Enable (WE) is LOW.
The CY7C197D is available in standard 24-Lead DIP and SOJ
Pb-Free Packages.
Logic Block Diagram
Pin Configurations
INPUT BUFFER
A₁₃
A₁₄
A₁₅
A₁₆
A₁₇
A₀
1024 x 256
A₁
ARRAY
A₂
A₃
A₄
COLUMN
DECODER
POWER
DOWN
A₅ A₆ A7 A₈ A₉ A₁₀ A₁₁ A₁₂
DI
DO
CE
WE
DIP/SOJ
Top View
A₀
A₁
A₂
A₃
A₄
A₅
A₆
A₇
A₈
D_OUT
WE
GND
1
24
2
23
3
22
4
21
5
20
6 ^7C197D ₁₉
7
18
8
17
9
16
10
15
11
14
12
13
V_CC
A₁₇
A₁₆
A₁₅
A₁₄
A₁₃
A₁₂
A₁₁
A₁₀
A₉
D_IN
CE
Selection Guide
Maximum Access Time (ns)
Maximum Operating Current (mA)
Maximum Standby Current (mA)
CY7C197D-10
10
60
3
CY7C197D-12
12
50
3
CY7C197D-15
15
40
3
Note:
1. For guidelines on SRAM system design, please refer to the “System Design Guidelines” Cypress application note, available on the internet at www.cypress.com.
Cypress Semiconductor Corporation • 3901 North First Street • San Jose, CA 95134 • 408-943-2600
Document #: 38-05458 Rev. *C
Revised January 11, 2005