AT28C040_09 Datasheet, PDF (1/15 Pages) ATMEL Corporation – 4-Megabit (512K x 8) Paged Parallel EEPROMs

Features
• Read Access Time – 200 ns
• Automatic Page Write Operation
– Internal Address and Data Latches for 256 Bytes
– Internal Control Timer
• Fast Write Cycle Time
– Page Write Cycle Time – 10 ms Maximum
– 1 to 256 Byte Page Write Operation
• Low Power Dissipation
– 50 mA Active Current
• Hardware and Software Data Protection
• DATA Polling for End of Write Detection
• High Reliability CMOS Technology
– Endurance: 10,000 Cycles
– Data Retention: 10 Years
• Single 5V ± 10% Supply
• CMOS and TTL Compatible Inputs and Outputs
• JEDEC Approved Byte-Wide Pinout
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