550 ns access — no write delays, no wear-out
The Cypress FM24W256-G is a 256Kbit non-volatile FRAM (Ferroelectric RAM) in the F-RAM™ series, organized as 32K x 8 bits and accessed over an I2C bus at up to 1 MHz. Unlike EEPROM, FRAM writes at bus speed — the 550 ns access time applies to both reads and writes, with no write-cycle delay or page-buffer management. That makes it a drop-in replacement for serial EEPROM in applications that log data frequently or need deterministic write timing: metering, industrial event recording, and black-box storage.
The supply range spans 2.7V to 5.5V, so the same BOM line works on a 3.3V MCU or a 5V legacy bus without a level translator on the I2C lines. The I2C interface is fully specified across that range, and the 1 MHz clock rate holds at both supply corners. For a board that already runs mixed-voltage logic, this part simplifies the memory subsystem — no extra regulator, no pull-up voltage divider.
The 8-SOIC package (3.90 mm width) reflows cleanly on standard FR-4 and is hand-reworkable with hot air — the 150-mil body is easy to align and the pinout is clear enough to reflow back without lifting a pad.