AT28C256 Paged Parallel EEPROM: Pinout, Equivalent and Datasheet

The following figure is the diagram of AT28C256 Pinout.

Pinout

The followings are AT28C256 Symbol and Footprint.

PCB Symbol

PCB Footprint

The AT28C256 is a high-performance Electrically Erasable and Programmable Read-Only Memory (EEPROM). Its 256-Kb memory is organized as 32,768 words by 8 bits. Manufactured with Microchip’s advanced nonvolatile CMOS technology, the device offers access times to 150 ns with power dissipation of just 440 mW. When the device is deselected, the CMOS standby current is less than 200 µA.

The AT28C256 is accessed like a Static RAM for the read or write cycle without the need for external components. The device contains a 64-byte page register to allow writing of up to 64 bytes simultaneously. During a write cycle, the address and 1 to 64 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. The AT28C256 has additional features to ensure high quality and manufacturability. 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 64 bytes of EEPROM for device identification or tracking.

This article provides you with a basic overview of the AT28C256 Paged Parallel EEPROM, including its pin descriptions, features and specifications, etc., to help you quickly understand what AT28C256 is.

● Fast Read Access Time: 150 ns

● Automatic Page Write Operation:

   ◆ Internally organized as 32,768 x 8 (256K)

   ◆ Internal address and data latches for 64 bytes

   ◆ Internal control timer

● Fast Write Cycle Time:

   ◆ Page Write cycle time: 3 ms or 10 ms maximum

   ◆ 1 to 64-byte Page Write operation

● Low-Power Dissipation:

   ◆ 50 mA active current

   ◆ 300 µA CMOS standby current

● Hardware and Software Data Protection

● DATA Polling for End of Write Detection

● High Reliability CMOS Technology:

   ◆ Endurance: 10,000 or 100,000 cycles

   ◆ Data retention: 10 years

● Single 5V ± 10% Supply

● CMOS and TTL Compatible Inputs and Outputs

● JEDEC^® Approved Byte-Wide Pinout

Microchip Technology AT28C256-15JU technical specifications, attributes, parameters and parts with similar specifications to Microchip Technology AT28C256-15JU.

The following is the Block Diagram of AT28C256.

Block Diagram

The following diagrams show the AT28C256 Package.

View A

View B

View C

The following diagram shows the AT28C256 Package Marking Information.

Topside

Backside

Microchip Technology Inc. is a leading provider of microcontroller and analog semiconductors, providing low-risk product development, lower total system cost and faster time to market for thousands of diverse customer applications worldwide. Headquartered in Chandler, Arizona, Microchip offers outstanding technical support along with dependable delivery and quality.