®

AS7C1026A

AS7C31026A

2/6/01; V.0.9

Alliance Semiconductor

P. 2 of 9

Functional description

The AS7C1026A and AS7C31026A are high-performance CMOS 1,048,576-bit Static Random Access Memory (SRAM) devices organized as

65,536 words × 16 bits. They are designed for memory applications where fast data access, low power, and simple interfacing are desired.

high-performance applications.

When CE is high the devices enter standby mode. The AS7C1026A is guaranteed not to exceed 55 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 (AS7C1026A) or 3.3V supply (AS7C31026A). 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 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

Parameter

Symbol

Min

Max

Unit

AS7C1026A

–0.50

+7.0

V

AS7C31026A

–0.50

+5.0

V

Voltage on any pin relative to GND

Both

–0.50

V

Power dissipation

Both

–1.0

W

Storage temperature (plastic)

Both

–65

+150

°C

Ambient temperature with VCC

applied

Both

–55

+125

°C

DC current into outputs (low)

Both

–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

LHL

L

H

High Z

LHL

H

L

High Z

LHL

L

L

LL

X

L

L

LL

X

L

H

High Z

LL

X

H

L

High Z

L

L

H

X

H

X

X

H

X

H

High Z

High Z