This document introduces the features and characteristics of the 256Kbit and 128Kbit serial I2C bus EEPROM M24128-BW, M24128-BR, M24256-BW, M24256-BR
The M24128 and M24256 devices are serial I²C‑compatible EEPROMs offered in 128‑Kbit (M24128) and 256‑Kbit (M24256) densities. They operate with three chip‑enable pins (E0, E1, E2) and support a two‑wire I²C interface up to 400 kHz. Supply voltage ranges are 2.5 V–5.5 V for the “‑BW” versions and 1.8 V–5.5 V for the “‑BR” versions. Features include byte and page writes (up to 64 bytes), random and sequential read modes, self‑timed programming cycles, and enhanced ESD/latch‑up protection.
The handbook contains a features summary, product list, package drawings, logic and signal diagrams, detailed electrical characteristics (DC and AC), mechanical dimensions for PDIP, SO and TSSOP packages, ordering information, and a revision history. It also describes power‑on reset behavior, device operation sequences, and write‑cycle timing.
| Supply voltage (‑BW versions) | 2.5 V to 5.5 V |
|---|---|
| Supply voltage (‑BR versions) | 1.8 V to 5.5 V |
| Maximum I²C bus speed | 400 kHz |
| Page‑write size | Up to 64 bytes per page |
| Erase/Write endurance | More than 1 Million cycles |
| Data retention | More than 40 years |
| Chip‑enable pins | Three (E0, E1, E2) |
They operate from 2.5 V to 5.5 V.
The devices are rated for more than one million erase/write cycles.
They support an I²C bus speed up to 400 kHz.
A page write can transfer up to 64 bytes.