General Description

The FM25C040U is a 4K (4,096) bit serial interface CMOS EEPROM (Electrically Erasable Programmable Read-Only Memory). This device fully conforms to the SPI 4-wire protocol which uses Chip Select (/CS), Clock (SCK), Data-in (SI) and Data out (SO) pins to synchronously control data transfer between the SPI microcontroller and the EEPROM. In addition, the serial interface allows a minimal pin count, packaging designed to simplify PC board layout requirements and offers the designer a variety of low voltage and low power options.

Features

■Sequential read of entire array

■4 byte Page write mode to minimize total write time per byte

■/WP pin and BLOCK WRITE protection to prevent inadvert ent programming as well as programming ENABLE and DISABLE opcodes.

■/HOLD pin to suspend data transfer

■Typical 1µA standby current (ISB) for L devices and 0.1µA standby current for LZ devices.

■Endurance: Up to 1,000,000 data changes

■Data retention greater than 40 years

Functions

■SPI MODE 0 interface

■4,096 bits organized as 512 x 8

■Extended 2.7V to 5.5V operating voltage

■2.1 MHz operation @ 4.5V - 5.5V

■Self-timed programming cycle

■Programming complete indicated by STATUS REGISTER polling

■/WP pin and BLOCK WRITE protection