Avoid the wrong density — 4Kbit is for calibration data, not firmware
The BR93G66FVM-3GTTR is a 4Kbit serial EEPROM from ROHM, organized as 256 x 16 bits, communicating over a Microwire interface at up to 3 MHz. This density tier is sized for storing calibration constants, serial numbers, or configuration parameters — not for firmware images or large data logs.
Temperature grade — industrial range, not extended hot-spot
It does not reach the 105°C or 125°C that some automotive-grade AEC-Q100 parts (like the BR93A46RFVT-WME2 or BR93H86RF-WCE2) carry, so for underhood or hot-plenum use, step up to those qualified parts.
Write cycle time — 5 ms word/page, plan your firmware loop
The write cycle time is 5 ms for both word and page operations. In a firmware routine that stores a parameter, budget a 5 ms polling wait or an interrupt timer — a tight loop that reads the status register too early will see a busy flag and waste cycles.
ROHS3 compliant and marked active in production.