8Kbit SPI EEPROM for parameter storage and calibration data
The 25LC080BT-I/SN is an 8Kbit serial EEPROM organized as 1K x 8 bits, accessed through an SPI bus at clock rates up to 10 MHz. The 10 MHz SPI clock lets you read or write the full memory in under 1 ms at the bus level, though each page write commits in 5 ms — budget that into your firmware update routine if you're writing more than one page in a tight loop. Industrial temperature range (-40°C to +85°C) makes it suitable for outdoor telecom cabinets, factory-floor PLCs, and automotive cabin modules where the ambient sees temperature swings but not engine-bay extremes.
SPI vs I²C — the bus trade-off for this density
The 25LC080BT-I/SN uses a 4-wire SPI interface (CS, SCK, MOSI, MISO), which consumes more GPIO pins than an I²C part but eliminates address conflicts on shared buses and gives you full-duplex data transfer. The closest functional peer in the same SOIC-8 footprint is the AT24C08D-SSHM-B, an 8Kbit I²C EEPROM running at 1 MHz. The two are not pin-compatible — the AT24C08D uses SDA and SCL instead of the SPI bus — so swapping them requires a board spin and firmware rewrite of the memory driver. If your design already has spare SPI pins and you need the faster clock rate, the 25LC080BT-I/SN is the cleaner fit. If you're constrained on GPIO count, the I²C alternative saves two pins at the cost of bus speed.