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ALLIANCE SEMICONDUCTOR

DID 11-20011-A. 5/22/00

AS7C1026

AS7C31026

Functional description

The AS7C1026 and AS7C31026 are high-performance CMOS 1,048,576-bit Static Random Access Memory (SRAM) devices

organized as 65,536 words x 16 bits. They are designed for memory applications where fast data access, low power, and simple

interfacing are desired.

are ideal for high-performance applications.

When CE is high the devices enter stanby mode. The AS7C1026 is guaranteed not to exceed 28 mW power consumption in

CMOS standby mode. The devices also offer 2.0V data retention.

A write cycle is accomplished by asserting write enable (WE) and chip enable (CE). Data on the input pins I/O0–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 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.

The 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/O0–I/O7, and UB controls the higher bits, I/O8–I/O15.

All chip inputs and outputs are TTL-compatible, and operation is from a single 5V supply (AS7C1026) or 3.3V supply

(AS7C31026). the device is packaged in common industry standard packages. Chip scale BGA packaging, easy to use in

manufacturing, provides the smallest possible footprint. This 48-ball JEDEC-registered package has a ball pitch of 0.75 mm and

external dimensions of 8 mm × 6 mm.

Absolute maximum ratings

Note: Stresses greater than those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stre ss 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. Exposure

to absolute maximum rating conditions for extended periods may affect reliability.

Truth table

Parameter

Symbol

Min

Max

Unit

AS7C1026

–0.50

+7.0

V

AS7C31026

–0.50

+5.0

V

Voltage on any pin relative to GND

–0.50

V

Power dissipation

–1.0

W

Storage temperature (plastic)

–65

+150

Ambient temperature with VCC applied

–55

+125

DC current into outputs (low)

–20

mA

CE

WE

OE

LB

UB

I/O0–I/O7

I/O8–I/O15

Mode

H

X

X

X

X

High Z

High Z

LH

L

L

H

High Z

LH

L

H

L

High Z

L

H

LLL

LL

X

L

L

LL

X

L

H

High Z