AS7C4098
AS7C34098
®
Functional description
The AS7C4098 and AS7C34098 are high-performance CMOS 4,194,304-bit Static Random Access Memory (SRAM) devices
organized as 262,144 words × 16 bits. They are designed for memory applications where fast data access, low power, and
simple interfacing are desired.
Equal address access and cycle times (t , t , t ) of 10/12/15/20 ns with output enable access times (t ) of 5/6/7/8 ns are
AA RC WC
OE
ideal for high-performance applications. The chip enable input CE permits easy memory expansion with multiple-bank
memory systems.
When CE is High the device enters standby mode. The standard AS7C4098/AS7C34098 is guaranteed not to exceed 110/
72mW power consumption in CMOS standby mode. A write cycle is accomplished by asserting write enable (WE) and chip
enable (CE). Data on the input pins I/O1–I/O16 is written on the rising edge of WE (write cycle 1) or CE (write cycle 2). To
avoid bus contention, external devices should drive I/O pins only after outputs have been disabled with output enable (OE) or
write enable (WE).
A read cycle is accomplished by asserting output enable (OE) and chip enable (CE), with write enable (WE) High. The chip
drives I/O pins with the data word referenced by the input address. When either chip enable or output enable is inactive, or
write enable is active, output drivers stay in high-impedance mode.
These devices provide multiple center power and ground pins, and separate byte enable controls, allowing individual bytes to
be written and read. LB controls the lower bits, I/O1–I/O8, and UB controls the higher bits, I/O9–I/O16.
All chip inputs and outputs are TTL- and CMOS-compatible, and operation is from either a single 5V (AS7C4098) or 3.3V
(AS7C34098) supply. Both devices are available in the JEDEC standard 400-mL, 44-pin SOJ and TSOP 2 packages.
Absolute maximum ratings
Parameter
Device
Symbol
Min
–0.50
–0.50
–0.50
–
Max
+7.0
+5.0
Unit
V
AS7C4098
AS7C34098
V
V
V
t1
t1
t2
D
Voltage on V relative to GND
CC
V
Voltage on any pin relative to GND
Power dissipation
V
+0.50
V
CC
P
T
1.5
W
Storage temperature
–65
–55
–
+150
+125
±20
°C
°C
mA
stg
bias
Ambient temperature with V applied
T
CC
DC current into outputs (low)
I
OUT
Note: Stresses greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only and
functional operation of the device at these or any other conditions outside those indicated in the operational sections of this specification is not implied.
Exposure to absolute maximum rating conditions for extended periods may affect reliability.
Truth table
CE
H
WE
X
OE
X
LB
X
X
H
L
UB
X
X
H
H
L
I/O1–I/O8
I/O9–I/O16
Mode
Standby (I , I
High Z
High Z
)
SB SB1
L
H
H
High Z
High Z
High Z
Output disable (I
)
CC
L
X
X
D
OUT
L
L
H
L
L
H
L
High Z
D
D
Read (I
)
CC
OUT
OUT
L
D
OUT
L
H
L
D
High Z
IN
X
H
L
High Z
D
D
Write (I
)
IN
IN
CC
L
D
IN
Key: X = Don’t care, L = Low, H = High.
1/13/05; v.1.9
Alliance Semiconductor
P. 2 of 10
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
