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ALLIANCE SEMICONDUCTOR
10/6/00
AS6UA5128
Functional description
The AS6UA5128 is a low-power CMOS 4,194,304-bit Static Random Access Memory (SRAM) device organized as
524,288 words × 8 bits. It is designed for memory applications where slow data access, low power, and simple interfacing
are desired.
Equal address access and cycle times (t
AA
, t
RC
, t
WC
) of 55/70ns are ideal for low-power applications. Active high and low
chip selects (CS) permit easy memory expansion with multiple-bank memory systems.
When CS is high, the device enters standby mode: the AS6UA5128 is guaranteed not to exceed 72
μ
W power consumption
at 3.6V and 55 ns; 41
μ
W at 2.7V and 70 ns; or 28
μ
W at 2.3V and 100 ns. The device also returns data when V
CC
is
reduced to 1.5V for even lower power consumption.
A write cycle is accomplished by asserting write enable (WE) and chip select (CS) low. Data on the input pins I/O1–I/O8 is
written on the rising edge of WE (write cycle 1) or CS (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), chip select (CS), with write enable (WE) High. The chip
drives I/O pins with the data word referenced by the input address. When either chip select or output enable is inactive, or
write enable is active, output drivers stay in high-impedance mode.
All chip inputs and outputs are CMOS-compatible, and operation is from a single 2.3V to 3.6V supply. The device is
available in the JEDEC standard 36(48)-ball FBGA package.
Absolute maximum ratings
Note: Stresses greater than those listed under
Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress rating only and func-
tional operation of the device at these or any other conditions outside those indicated in the operational sections of this spec ification is not implied. Expo-
sure to absolute maximum rating conditions for extended periods may affect reliability.
Truth table
Key: X = Don’t care, L = Low, H = High.
Parameter
Device
Symbol
Min
Max
Unit
Voltage on V
CC
relative to V
SS
Voltage on any I/O pin relative to GND
Power dissipation
V
tIN
V
tI/O
P
D
T
stg
T
bias
I
OUT
–0.5
V
CC
+ 0.5
V
–0.5
–
V
W
°
C
°
C
mA
1.0
Storage temperature (plastic)
–65
+150
Temperature with V
CC
applied
DC output current (low)
–55
–
+125
20
CS
WE
OE
Supply Current
I/O1–I/O8
Mode
H
L
X
X
X
X
I
SB
High Z
Standby (I
SB
)
L
H
H
I
CC
I
CC
I
CC
High Z
Output disable (I
CC
)
Read (I
CC
)
Write (I
CC
)
L
L
H
L
L
X
D
OUT
D
IN