STMicroelectronics M24256-BWMN6P

Overview

M24256-BWMN6P from STMicroelectronics is a 256-Kbit I²C-compatible EEPROM organized as 32 K × 8 bits, operating from 2.5 V to 5.5 V with 1 MHz clock support. It features 64-byte page write, hardware write protection via WC pin, and enhanced ESD/latch-up immunity. Used in industrial control modules for parameter storage and calibration data retention.

For engineers reviewing the M24256-BWMN6P datasheet, M24256-BWMN6P pinout, M24256-BWMN6P application, or M24256-BWMN6P equivalent, this page delivers verified package mapping (SO8N/MN), validated I²C timing compliance (100 kHz/400 kHz/1 MHz), confirmed memory organization (32 Kbyte × 8), and real-world design constraints including WC-controlled full-array lock and ECC-protected read reliability.

Technical Context

The device implements a slave-only I²C interface with fixed 7-bit device address (1010xxxR/W) decoded against E2–E0 inputs, supporting random, current-address, and sequential read modes. Internal address counter auto-increments on read completion and wraps at 32 K boundary.

Write operations are gated by WC pin state and use internal charge pump for byte/page programming. ECC logic operates transparently across 4-byte groups, correcting single-bit errors during reads while distributing write cycles across group members to extend endurance beyond 4 million cycles.

Key Specifications

Pinout & Package

Package: SO8N (MN), 150 mil width, RoHS-compliant ECOPACK2.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar I²C EEPROM applications.

Compared with AT24C256-10PU-2.7 and BR24G256FJ-WE2, M24256-BWMN6P uniquely combines hardware write lock, on-the-fly ECC, and 1 MHz I²C speed within a standard SO8N package - delivering higher functional safety assurance without increasing PCB area or firmware complexity.

Availability

M24256-BWMN6P is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, automotive body control modules, and smart energy metering requiring stable component supply across multi-year production cycles.

Supply support for M24256-BWMN6P includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, designing and manufacturing microcontrollers, power ICs, sensors, and memory solutions for industrial, automotive, and consumer markets.

M24256-BWMN6P belongs to ST's M24 serial EEPROM product line, engineered specifically for robust, low-power, high-reliability nonvolatile storage in harsh environments where data integrity and long-term retention are mission-critical.

FAQ

What is the function of the WC pin on M24256-BWMN6P?

The WC (Write Control) pin is an active-high hardware lock that disables all write operations to the entire 32 Kbyte memory array when driven high. When WC is low or floating, writes are enabled. This feature prevents accidental overwrites during power-up, firmware updates, or debug sessions - a critical safety mechanism for production systems.

Does M24256-BWMN6P support 1 MHz I²C communication at 2.5 V supply?

Yes. The M24256-BWMN6P is fully specified for 1 MHz I²C operation across its entire 2.5 V to 5.5 V supply range. This is confirmed in Section 1 of the DS1766 datasheet (Rev 35), which states "1 MHz clock from 1.7 V to 5.5 V" for the -BF/-DF variants and "1 MHz clock from 2.5 V to 5.5 V" for the -BW/-BR variants - matching the -BWMN6P's voltage rating.

How does the ECC feature operate in M24256-BWMN6P?

ECC operates transparently on every 4-byte group (addresses 4N to 4N+3). During reads, it detects and corrects single-bit errors without CPU intervention. During writes, cycling one byte automatically cycles all four bytes in its group - limiting total endurance to 4 million cycles per group, not per byte. This trade-off ensures data reliability without requiring firmware-level error handling.

Can M24256-BWMN6P be used in place of M24256-BW in existing designs?

Yes - M24256-BWMN6P is a variant of the M24256-BW family with SO8N (MN) packaging. It shares identical electrical specifications, timing, pinout, and functionality with the base M24256-BW. The "MN" suffix denotes the 150 mil SO8N package per ST's ordering code convention, making it a direct drop-in replacement where that footprint is used.