64Kbit I2C EEPROM in a 4-bump WLCSP
The STMicroelectronics M24C64X-FCU6T/TF is a 64Kbit serial EEPROM with an I2C interface, organized as 8K x 8 bits. The part is clocked at up to 1 MHz and features a 650 ns access time and a 5 ms write cycle time for word or page writes.
Supply voltage and system compatibility
It directly answers the question of whether this EEPROM works in a 3.3V or 5V system — it works in both, without a level shifter. This eliminates a common BOM headache when the same design needs to span a product family with different core voltages. The 1 MHz clock rate is the I2C fast-mode plus ceiling, so the bus timing budget is generous for most MCUs.
Package and footprint for space-constrained boards
The footprint is tiny — roughly 0.71 mm by 0.73 mm — which is the primary reason to select this variant over a larger SOIC or TSSOP.
There is no last-time-buy or phase-out risk on the immediate horizon.