DESCRIPTION
The Microchip Technology Inc. 25AA640/25LC640/ 25C640 (25xx640*) is a 64K bit serial Electrically Erasable PROM. The memory is accessed via a simple Serial Peripheral Interface (SPI) compatible serial bus. The bus signals required are a clock input (SCK) plus separate data in (SI) and data out (SO) lines. Access to the device is controlled through a chip select (CS) input.

FEATURES
• Low power CMOS technology
    - Write current: 3 mA typical
    - Read current: 500 µA typical
    - Standby current: 500 nA typical
• 8192 x 8 bit organization
• 32 byte page
• Write cycle time: 5ms max.
• Self-timed ERASE and WRITE cycles
• Block write protection
    - Protect none, 1/4, 1/2, or all of array
• Built-in write protection
    - Power on/off data protection circuitry
    - Write enable latch
    - Write protect pin
• Sequential read
• High reliability
    - Endurance: 1M cycles (guaranteed)
    - Data retention: > 200 years
    - ESD protection: > 4000 V
• 8-pin PDIP, SOIC, and TSSOP packages
• Temperature ranges supported:
    - Commercial: (C) 0°C to +70°C
    - Industrial: (I) -40°C to +85°C
    - Automotive: (E) (25C640) -40°C to +125°C