Microchip 25AA040A-I/MS is a 4 Kbit Serial Electrically Erasable Programmable Read-Only Memory (EEPROM). 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. Communication to the device can be paused via the hold pin (HOLD).

Max. Clock 10 MHz
Low-Power CMOS Technology: Max. Write Current: 5 mA at 5.5V, 10 MHz, Read Current: 5 mA at 5.5V, 10 MHz, Standby Current: 5 μA at 5.5V
Sequential Read
Self-timed Erase and Write Cycles (5 ms max.)
Built-in Write Protection: Power-on/off data protection circuitry, Write enable latch, Write-protect pin
High Reliability: Endurance: 1,000,000 Erase/Write cycles, Data retention: >200 years, ESD protection: >4000V
Temperature Ranges Supported: Industrial (I): -40°C to +85°C, Automotive (E): -40°C to +125°C
Pb-Free and RoHS Compliant