Features

– Internal Address and Data Latches for 256 Bytes

– Internal Control Timer

– Page Write Cycle Time – 10 ms Maximum

– 1 to 256 Byte Page Write Operation

– 50 mA Active Current

– Endurance: 10,000 Cycles

– Data Retention: 10 Years

1.

Description

The AT28C040 is a high-performance electrically erasable and programmable read-

only memory (EEPROM). Its 4 megabits of memory is organized as 524,288 words by

8 bits. Manufactured with Atmel’s advanced nonvolatile CMOS technology, the device

offers access times to 200 ns with power dissipation of just 440 mW.

The AT28C040 is accessed like a static RAM for the read or write cycle without the

need for external components. The device contains a 256-byte page register to allow

writing of up to 256 bytes simultaneously. During a write cycle, the address and 1 to

256 bytes of data are internally latched, freeing the address and data bus for other

operations. Following the initiation of a write cycle, the device will automatically write

the latched data using an internal control timer. The end of a write cycle can be

detected by Data Polling of I/O7. Once the end of a write cycle has been detected, a

new access for a read or write can begin.

Atmel's AT28C040 has additional features to ensure high quality and manufacturabil-

ity. The device utilizes internal error correction for extended endurance and improved

data retention characteristics. An optional software data protection mechanism is

available to guard against inadvertent writes. The device also includes an extra 256

bytes of EEPROM for device identification or tracking.

4-Megabit

(512K x 8)

Paged Parallel

EEPROMs

AT28C040

0542F–PEEPR–2/09