STMicroelectronics M24256-DRDW3TP/K

Overview

M24256-DRDW3TP/K from STMicroelectronics is a 256-Kbit I²C-compatible serial EEPROM organized as 32 K × 8 bits, featuring an additional 64-byte identification page with permanent lock capability. It operates across 1.7 V to 5.5 V supply, supports 1 MHz I²C clock, and delivers byte/page write within 5 ms - used in industrial control modules for secure parameter storage and firmware revision tracking.

For engineers reviewing the M24256-DRDW3TP/K datasheet, M24256-DRDW3TP/K pinout, M24256-DRDW3TP/K application, or M24256-DRDW3TP/K equivalent, key selection factors include its extended voltage range (1.7–5.5 V), identification page lockability, TSSOP8 ECOPACK2 packaging, and enhanced ESD/latch-up protection for harsh environments.

Technical Context

The device implements a fully compliant I²C slave interface with start/stop detection, ACK/NACK handshaking, and address decoding using three chip-enable inputs (E2–E0) to configure the 7-bit device select code. Its internal architecture includes an HV generator, ECC logic across 4-byte groups, and a page latch supporting 64-byte page writes without roll-over within the same page boundary.

Write control (WC) input enables hardware-level memory protection: when high, all write operations-including byte, page, and identification page writes-are inhibited, while read operations remain fully functional. The identification page (accessible via device type identifier 1011b) supports dedicated lock/unlock instructions and retains data for >200 years with >4 million write cycles per group.

Key Specifications

Pinout & Package

TSSOP8 (DW) package, 169 mil width, RoHS-compliant and halogen-free (ECOPACK2). Pin 1 marked by notch or dot; top-view orientation follows standard JEDEC layout.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C256C-SSHL-T and BR24G256FJ-WE2, M24256-DRDW3TP/K uniquely combines hardware write control, ECC-per-group reliability, and a permanently lockable identification page - making it optimal for safety-critical, long-lifecycle industrial and medical applications requiring tamper resistance and extended voltage margin.

Availability

M24256-DRDW3TP/K is available at Aetrix Electronics and suitable for industrial sensor calibration, medical device configuration, and automotive body control modules requiring stable component supply and long-term lifecycle support.

Supply support for M24256-DRDW3TP/K 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.

This device belongs to the M24xxx series of I²C EEPROMs engineered for robustness in harsh environments - emphasizing extended voltage range, hardware write protection, and long-term data integrity for mission-critical embedded systems.

FAQ

What is the function of the WC pin on M24256-DRDW3TP/K?

The WC (Write Control) pin is an active-high hardware lock that disables all write operations - including byte, page, and identification page writes - while allowing unrestricted read access. When driven high, the device acknowledges device select and address bytes but returns NoAck for data bytes, preventing accidental or malicious overwrites. This feature is critical for protecting calibration data or security keys in deployed systems.

How does the identification page differ from the main memory array?

The identification page is a dedicated 64-byte section accessible via I²C device type identifier 1011b (vs. 1010b for main memory). It supports two unique instructions: write identification page and lock identification page. Once locked, it becomes permanently read-only - unlike the main array, which remains fully writable. This separation enables secure storage of immutable parameters such as cryptographic keys or device serial numbers.

Does M24256-DRDW3TP/K support standard I²C addressing with multiple devices on one bus?

Yes - the E2, E1, and E0 pins configure the three least significant bits of the 7-bit I²C device address (b2–b0), enabling up to eight M24256-DRDW3TP/K devices on a single bus. Each device responds only when its E2–E0 state matches the corresponding bits in the received device select code (1010xxxx for main memory or 1011xxxx for ID page). Floating E pins default to logic low, simplifying single-device configurations.

What is the role of ECC in M24256-DRDW3TP/K, and how does it affect endurance?

ECC operates transparently across every 4-byte group (addresses 4N–4N+3), correcting single-bit errors during reads. During writes, all four bytes in the group are cycled together - meaning endurance is rated per group, not per byte. The sum of write cycles across the four bytes must stay ≤4 million. This design extends effective lifetime in applications with frequent partial-page updates, such as logging or counter storage.