1 Kbit serial EEPROM in a SOT-23-6 — what it fits
The Microchip 93C46BT-I/OT is a 1Kbit serial EEPROM using the Microwire interface, organized as 64 words of 16 bits each.
Supply rail and interface — classic 5V Microwire
This part needs a 5V rail (4.5V to 5.5V), so it won't run on a 3.3V supply without a level shifter. The Microwire interface uses three wires (SI, SO, SK) plus chip select — it is not I2C or SPI, so the MCU must have a dedicated Microwire peripheral or bit-banged GPIO. The 2 MHz clock is fast enough for most configuration-storage reads; the 2ms write cycle is typical for EEPROM and determines how quickly you can update parameters.
Memory organization — 64 x 16
Organized as 64 words of 16 bits each, the 93C46BT-I/OT addresses each word individually. This 16-bit word width differs from the 128 x 8 organization of the 93C46A variant — if your firmware expects byte-wide access, check the addressing scheme. The 1Kbit total is enough for serial number, calibration constants, or a small lookup table.
Lifecycle — active, no end-of-life concern
The ROHS3 compliance is current.