Microchip Technology 25AA640-I/SN Memory IC SOIC-8 25AA640-I/SN Data Sheet

© 2008 Microchip Technology Inc.

DS21223H-page 1

• Low-Power CMOS Technology

- Write current: 3 mA, typical

- Read current: 500

μ

A, typical

- Standby current: 500 nA, typical

• 8192 x 8 Bit Organization

• 32 Byte Page

• Write Cycle Time: 5 ms max.

• Self-Timed Erase and Write Cycles

• Block Write Protection

- Protect none, 1/4, 1/2 or all of array

• Built-in Write Protection

- Power on/off data protection circuitry

- Write enable latch

- Write-protect pin

• Sequential Read

• High Reliability

- Data retention: > 200 years

- ESD protection: > 4000V

• 8-pin PDIP, SOIC and TSSOP Packages

• Temperature Ranges Supported:

- Industrial (I): -40

°C to +85°C

- Automotive (E): -40

°C to +125°C

The Microchip Technology Inc. 25AA640/25LC640
(25XX640

*

) is a 64 Kbit Serial Electrically Erasable

PROM [EEPROM]. The memory is accessed via a
simple Serial Peripheral Interface (SPI) compatible
serial bus. The bus signals required are a clock input
(SCK) plus separate data in (SI) and data out (SO)
lines. Access to the device is controlled through a Chip
Select (CS) input. 

Communication to the device can be paused via the
hold pin (HOLD). While the device is paused,
transitions on its inputs will be ignored, with the
exception of Chip Select, allowing the host to service
higher priority interrupts. 

25AA640

1.8-5.5V

1 MHz

I

25LC640

2.5-5.5V

2 MHz

I

25LC640

4.5-5.5V

3/2.5 MHz

I, E

SI

SO

SCK

CS

HOLD

WP

I/O Control

Memory

Control

Logic

HV Generator

EEPROM

Array

Page 

Y Decoder

Sense Amp.
R/W Control

Logic

V

CC

V

SS

Latches

XDEC

STATUS

Register

CS

SO

WP

V

SS

V

CC

HOLD

SCK

SI

8

7

6

5

1

2

3

4

8
7
6
5

1
2
3
4

HOLD

V

CC

CS

SO

SCK
SI
V

SS

WP

*25XX640 is used in this document as a generic part number for the 25AA640/25LC640 devices.