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 (tAA, tRC, tWC) 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 µW power consumption at
3.6V and 55 ns; 41 µW at 2.7V and 70 ns; or 28 µW at 2.3V and 100 ns. The device also returns data when VCC 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
Parameter
Voltage on VCC relative to VSS
Voltage on any I/O pin relative to GND
Power dissipation
Device
Symbol
VtIN
Min
–0.5
–0.5
–
Max
Unit
V
VCC + 0.5
VtI/O
PD
V
1.0
+150
+125
20
W
Storage temperature (plastic)
Temperature with VCC applied
DC output current (low)
Tstg
–65
–55
–
°C
°C
mA
Tbias
IOUT
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
CS
H
L
WE
X
OE
X
Supply Current
ISB
I/O1–I/O8
High Z
Mode
Standby (ISB)
X
X
L
H
H
L
H
L
ICC
ICC
ICC
High Z
DOUT
DIN
Output disable (ICC
)
L
Read (ICC
)
L
X
Write (ICC)
Key: X = Don’t care, L = Low, H = High.
5/25/01; v.1.1
Alliance Semiconductor
P. 2 of 9
ALSC [ ALLIANCE SEMICONDUCTOR CORPORATION ]
