 2004 Microchip Technology Inc.

DS11126H-page 1

FEATURES

• Fast Read Access Time—150 ns

• CMOS Technology for Low Power Dissipation

- 30 mA Active

- 100

µA Standby

• Fast Byte Write Time—200

µs or 1 ms

• Data Retention >200 years

- Automatic Write Operation

- Internal Control Timer

- Auto-Clear Before Write Operation

- On-Chip Address and Data Latches

•Data Polling

• Chip Clear Operation

• Enhanced Data Protection

- Pulse Filter

- Write Inhibit

• 5-Volt-Only Operation

• Organized 512x8 JEDEC standard pinout

- 24-pin Dual-In-Line Package

- 32-pin PLCC Package

• Available for Extended Temperature Ranges:

- Commercial: 0°C to +70°C

- Industrial: -40°C to +85°C

DESCRIPTION

The Microchip Technology Inc. 28C04A is a CMOS 4K

non-volatile electrically Erasable and Programmable

Read Only Memory (EEPROM). The 28C04A is

accessed like a static RAM for the read or write cycles

without the need of external components. During a

“byte write”, the address and data are latched inter-

nally, freeing the microprocessor address and data bus

for other operations. Following the initiation of write

cycle, the device will go to a busy state and automati-

cally clear and write the latched data using an internal

control timer. To determine when a write cycle is com-

plete, the 28C04A uses Data polling. Data polling

allows the user to read the location last written to when

the write operation is complete. CMOS design and pro-

cessing enables this part to be used in systems where

reduced

power

consumption

and

reliability

are

required. A complete family of packages is offered to

provide the utmost flexibility in applications.

PACKAGE TYPES

BLOCK DIAGRAM

• 1

2

3

4

5

6

7

8

9

10

11

12

24

23

22

21

20

19

18

17

16

15

14

13

A7

A6

A5

A4

A3

A2

A1

A0

I/O0

I/O1

I/O2

V

Vcc

A8

NC

WE

OE

NC

CE

I/O7

I/O6

I/O5

I/O4

I/O3

SS

A6

A5

A4

A3

A2

A1

A0

NC

I/O0

A8

NC

NC

NC

OE

NC

CE

I/O7

I/O6

29

28

27

26

25

24

23

22

21

5

6

7

8

9

10

11

12

13

DIP

PLCC

• Pin 1 indicator on PLCC on top of package

I/O0

I/O7

Input/Output

Buffers

Chip Enable/

Output Enable

Control Logic

CE

OE

Data Protection

Circuitry

A8

Y Gating

4K bit

Cell Matrix

X

Decoder

Y

Decoder

A0

Data

Poll

Auto Erase/Write

Timing

WE

L

a

t

c

h

e

s

Program Voltage

Generation

28C04A

4K (512 x 8) CMOS EEPROM

Obsolete Device