STMicroelectronics M24256-BWDW6TP

Overview

M24256-BWDW6TP from STMicroelectronics is a 256-Kbit I²C-compatible serial EEPROM organized as 32 K × 8 bits, operating as a nonvolatile memory slave device on standard and fast-mode I²C buses (up to 1 MHz). It features 64-byte page write capability, 1.7 V to 5.5 V single-supply operation, and hardware write protection via WC pin. Used in industrial control modules for parameter storage and calibration data retention.

For engineers reviewing the M24256-BWDW6TP datasheet, M24256-BWDW6TP pinout, M24256-BWDW6TP application, or M24256-BWDW6TP equivalent, key selection factors include I²C clock compatibility (100 kHz/400 kHz/1 MHz), TSSOP8 package footprint, full-array write lock via WC input, ECC-enabled read reliability, and guaranteed 4 million write cycles with 200-year data retention at +85 °C.

Technical Context

The M24256-BWDW6TP implements a dedicated I²C slave interface with start/stop detection, ACK/NACK handshaking, and automatic address counter incrementing during sequential reads. Its internal architecture includes an HV generator for EEPROM programming, ECC logic applied per 4-byte group, and a POR circuit preventing spurious writes during power ramp.

Chip enable is implemented via three hard-wired inputs (E2, E1, E0), allowing up to eight devices on one bus using unique 3-bit device addressing. Write control (WC) disables all write operations-including byte, page, and identification page writes-when driven high, independent of I²C transaction state.

Key Specifications

Pinout & Package

TSSOP8 (DW) package: 8-lead thin shrink small outline package, 169 mil body width, 0.65 mm lead pitch, RoHS-compliant and halogen-free (ECOPACK2).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C256-SSHL-T and BR24G256FJ-WE2, the M24256-BWDW6TP uniquely combines hardware write control (WC), per-group ECC, and ECOPACK2 compliance in TSSOP8 - making it optimal for industrial and medical designs where data integrity and physical write prevention are design-critical.

Availability

M24256-BWDW6TP is available at Aetrix Electronics and suitable for industrial PLCs, smart meters, medical device serialization, and automotive body control modules requiring stable component supply, long-term lifecycle support, and RoHS-compliant sourcing.

Supply support for M24256-BWDW6TP 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.

The M24256 series belongs to ST's serial EEPROM product line, engineered specifically for robust, low-power, I²C-based nonvolatile storage in harsh environments - emphasizing reliability, extended temperature operation, and hardware-level data protection.

FAQ

Does M24256-BWDW6TP support 1 MHz I²C operation across its full voltage range?

Yes. The device supports 1 MHz clock frequency from 1.7 V to 5.5 V, as verified in DS1766 Rev 35 AC characteristics (Table 10). This enables high-speed parameter loading in systems using 3.3 V or 5 V MCUs without clock throttling or external speed negotiation.

What happens if the WC pin is left unconnected (floating)?

When WC is floating, it is internally pulled low, enabling write operations. However, ST recommends explicitly tying WC to VSS (for enabled writes) or VCC (for disabled writes) to prevent noise-induced toggling - especially in high-EMI industrial environments where floating pins may cause intermittent write failures.

Is the M24256-BWDW6TP pin-compatible with other variants like M24256-BR or M24256-BF?

Yes - all M24256 variants in TSSOP8 (DW) share identical pinout and footprint. Differences lie in voltage range (BWDW6TP: 1.7–5.5 V; BWR: 1.8–5.5 V; BFW: 1.7–5.5 V) and feature set (e.g., ID page only in -D suffix parts), not pin assignment or mechanical layout.

How does the ECC function impact endurance specifications?

ECC operates transparently per 4-byte group: writing any byte also cycles the other three bytes in its group. Endurance is specified per group (4 million cycles total across all four bytes), not per individual address - meaning distributed writes across a group extend usable life versus concentrated writes to a single location.