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AS4C14400

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Functional description

The AS4C14400 is a high performance CMOS Dynamic Random Access Memory organized as 1,048,576 words × 4 bits. The AS4C14400 is

fabricated with advanced CMOS technology and designed with innovative design techniques resulting in high speed, extremely low power

and wide operating margins at component and system levels.

The AS4C14400 features a high speed page mode operation in which high speed read, write and read-write are performed on any of the

1024

× 4 bits defined by the column address. The asynchronous column address uses an extremely short row address capture time to ease

the system level timing constraints associated with multiplexed addressing. Output is tri-stated by a column address strobe (CAS) which acts

as an output enable independent of RAS. Very fast CAS to output access time eases system design.

Refresh on the 1024 address combinations of A0 to A9 during a 16 ms period is accomplished by performing any of the following:

•RAS-only refresh cycles

• Hidden refresh cycles

•CAS-before-RAS refresh cycles

• Normal read or write cycles

The AS4C14400 is available in JEDEC standard 20/26-pin plastic SOJ and 20/26-pin plastic TSOP packages. System level features include

single power supply of 5.0

± 0.5V tolerance and direct interface with TTL logic families.

Logic block diagram

Recommended operating conditions

Recommended operating conditions apply to all specifications unless otherwise noted.

Parameter

Symbol

Minimum

Nominal

Maximum

Unit

Supply voltage

4.5

5.0

5.5

V

GND

0.0

0.0

0.0

V

Input voltage

2.4

–

V

–1.0

–

0.8

V

Operating temperature

TA

0

70

°C

1024 × 1024 × 4

Array

(4,194,304)

Sense amp

A0

A1

A2

A3

A4

A5

A6

A7

I/O0

I/O3

Vcc

GND

A8

I/O2

I/O1

Column decoder

Data

I/O

OE

RAS

CAS

WE

A9

RAS clock

generator

CAS clock

generator

WE clock

generator