AS7C31026C
9/20/06, v 1.0 Alliance Memory P. 2 of 10
®
Functional description
The AS7C31026C is a 3V high-performance CMOS 1,048,576-bit Static Random Access Memory (SRAM) device organized
as 65,536 words × 16 bits. It is designed for memory applications where fast data access, low power, and simple interfacing
are desired.
Equal address access and cycle times (tAA, tRC, tWC) of 10 ns with output enable access times (tOE) of 5 ns are ideal for high-
performance applications.
When CE is high, the device enters standby mode. A write cycle is accomplished by asserting write enable (WE) and chip
enable (CE). Data on the input pins I/O0 through I/O15 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 chips
drive I/O pins wit h the data word referenced by t he input add ress. When either chip enable or output enable is inactive or write
enable is active, output drivers stay in high-impedance mode.
The device provides 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/O0 through I/O7, and UB controls the higher bits, I/O8 through I/O15.
All chip inputs and ou tputs are TTL-compatibl e, and operation is from a single 3.3 V suppl y. The AS7C31026C is packaged in
common industry standard packages.
Note: Stresses greater than those listed under Absolute Maximum Ratings may cau se permanent damage to the device. This is a stress rating only and func -
tional operation of the devic e at these or any other co nditions outsid e those indicated in the operational sectio ns of this specification is not implied. Exposure
to absolute maximum rating co nditions for extended periods may affect reliability.
Key: H = high, L = low, X = don’t care.
Absolute maximum ratings
Parameter Symbol Min Max Unit
Voltage on VCC relative to GND Vt1 –0.50 +4.60 V
Voltage on any pin rela tive to GND Vt2 –0.50 VCC +0.50 V
Power dissipation PD–1.25W
Storage temperature (plastic) Tstg –55 +125 °C
Ambient temperature with VCC applied Tbias –55 +125 °C
DC current into outputs (low) IOUT –50mA
Truth table
CE WE OE LB UB I/O0–I/O7 I/O8–I/O15 Mode
HXXXXHigh ZHigh Z Standby (I
SB), ISBI)
LHLLHD
OUT High Z Read I/O0–I/O7 (ICC)
LHLHLHigh ZD
OUT Read I/O8–I/O15 (ICC)
LHLLLD
OUT DOUT Read I/O0–I/O15 (ICC)
LLXLL D
IN DIN Write I/O0–I/O15 (ICC)
LLXLH D
IN High Z Write I/O0–I/O7 (ICC)
LLXHLHigh ZD
IN Write I/O8–I/O15 (ICC)
L
LH
XH
XX
HX
HHigh Z High Z Output disable (ICC)