The Microchip AT28HC256 is a high-performance 256Kbit Parallel EEPROM available in both Industrial and Military temp ranges, offering access times to 70ns with power dissipation of 440mW. Deselected, CMOS standby current is less than 5mA. Accessed like static RAM for the read or write cycle without external components, it contains a 64-byte page register to allow writing of up to 64 bytes simultaneously. Features an internal Error Correction Circuit for extended endurance and improved data retention, in Military version. Optional Software Data Protection mechanism guards against inadvertent writes; and an extra 64 bytes of EEPROM enables device identification or tracking.

The AT28HC256 is also available DUAL MARKED where applicable with the appropriate Standard Military Drawing Number - 5962-886340xxx.  See the datasheet for exact MIL product availability.

• 32 Kbits x 8 (256 Kbit)
• 5V ± 10% Supply
• Parallel Interface
• AT28HC256E - High Endurance 100K Write Cycles Option
• AT28HC256F - 3 ms Fast Write Option
• 70ns access time
• Self-Timed Erase and Write Cycles (10 ms max)
• Page Write and Byte Write
• Data Polling for end of write detection
• Low Power Consumption
• Read / Write current 80 mA (Max)
• Standby current TTL 3 mA (Max), CMOS 300 μA (Max)
• Write-Protection
• Hardware Protection
• Software Data Protect
• Data retention > 10 years
• Temperature Ranges
• Standard Temperature Range: -40°C to 85°C
• Military Temperature Range: -55°C to 125°C
• Available in Green (Pb/Halide-free) Packaging
• 32-lead, Plastic J-leaded Chip Carrier (PLCC)
• 28-lead, 0.300" Wide, Plastic Gull Wing Small Outline (SOIC)
• 28-lead, Plastic Thin Small Outline Package (TSOP)
• Available in Dual marked (5962-886340xxx) CERAMIC Hermetic Packaging
• 28-Lead, 0.600" Wide, Non-Windowed, Ceramic Dual Inline (Cerdip)
• 28-Lead, Non-Windowed, Ceramic Bottom-Brazed Flat Package (Flatpack)
• 32-Pad, Non-windowed, Ceramic, Leadless Chip Carrier (LCC)