2 Kbit I²C EEPROM for configuration storage
The STMicroelectronics M24C02-WMN6P is a 2 Kbit serial EEPROM with an I²C interface, organized as 256 words by 8 bits. The part supports a 400 kHz clock frequency and delivers a 900 ns access time, which is typical for fast-mode I²C EEPROMs. Write operations complete in 5 ms per word or page. The memory is non-volatile, retaining data without power.
NRND — plan a replacement for new designs
While existing production can continue using stocked inventory or last-time-buy quantities, any new BOM should target a pin-compatible replacement within the M24C02 family or a similar I²C EEPROM from ST or another vendor.
What the 900 ns access time and 5 ms write cycle mean for your bus
The 900 ns access time is the delay from the I²C address byte to the first data byte appearing on the bus. At 400 kHz, the SCL period is 2.5 µs, so the access time adds less than one clock cycle of wait — the MCU can poll the part without stalling the bus. The 5 ms write cycle is the time the EEPROM needs to program the internal array after a write command; during this window the part does not acknowledge its address, so the host must retry or wait. For small configuration blocks (a few bytes), this is transparent. For streaming writes, budget the 5 ms per page.