Infineon Technologies FM24W256-EGTR

Overview

FM24W256-EGTR from Cypress Semiconductor is a 256-Kbit (32K × 8) serial I²C F-RAM nonvolatile memory with NoDelay™ write capability, 10¹⁴ read/write endurance, and 151-year data retention at +85 °C. It operates from 2.7 V to 5.5 V across –40 °C to +85 °C and serves as a hardware-compatible drop-in replacement for I²C EEPROM in real-time data logging and industrial control systems.

For engineers reviewing the FM24W256-EGTR datasheet, FM24W256-EGTR pinout, FM24W256-EGTR application, or FM24W256-EGTR equivalent, key selection criteria include write-speed-critical embedded logging, high-cycle-count sensor buffering, industrial temperature resilience, and I²C bus timing compatibility at up to 1 MHz.

Technical Context

The FM24W256-EGTR implements a ferroelectric memory array logically organized as 32,768 × 8 bits, accessed via standard I²C protocol with 7-bit slave address (1010b + A2–A0) and two-byte memory addressing. It supports full I²C timing modes: 100 kHz, 400 kHz, and 1 MHz.

Its internal address latch auto-increments after each byte transfer, enabling unlimited sequential reads/writes without re-addressing. Write operations complete at bus speed-no polling or delay cycles required-and the WP pin provides hardware-level write protection over the entire memory map.

Key Specifications

Pinout & Package

FM24W256-EGTR is housed in an 8-pin SOIC package (width: 3.9 mm), RoHS-compliant, with gull-wing leads and standard JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT24C256B-PU and MB85RC256V, FM24W256-EGTR delivers the highest endurance (10¹⁴ cycles) and longest data retention (151 years at +85 °C) within its industrial temperature class, making it optimal for mission-critical, high-write-frequency applications where EEPROM wear-out or FRAM temperature margin is not the primary constraint.

Availability

FM24W256-EGTR is available at Aetrix Electronics and suitable for smart energy metering, industrial PLC data buffering, and medical diagnostic equipment requiring stable component supply and guaranteed long-term availability.

Supply support for FM24W256-EGTR 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

Cypress Semiconductor (now part of Infineon Technologies) designs high-reliability nonvolatile memory and programmable system-on-chip solutions for industrial, automotive, and IoT applications.

The FM24W256-EGTR belongs to Cypress's F-RAM product line, engineered specifically to replace EEPROM in write-intensive, low-power, and thermally demanding embedded systems without compromising data integrity or timing predictability.

FAQ

Is FM24W256-EGTR pin-compatible with standard I²C EEPROMs like AT24C256?

Yes, FM24W256-EGTR uses an 8-pin SOIC package with identical pinout (VDD, VSS, SDA, SCL, WP, A0–A2) and I²C electrical signaling. It accepts the same 7-bit slave address format (1010b + A2–A0) and supports legacy 100 kHz and 400 kHz timings, enabling direct PCB-level replacement without layout changes.

Does FM24W256-EGTR require special I²C initialization or firmware modifications?

No. The device behaves identically to standard I²C EEPROMs during address transmission, ACK/NACK handshaking, and sequential read/write sequences. Firmware only benefits from removing write-polling loops due to NoDelay™ operation-no driver or protocol stack changes are needed for basic functionality.

What is the maximum supported I²C bus capacitance for reliable 1-MHz operation?

Per the datasheet, reliable 1-MHz operation requires total bus capacitance ≤ 200 pF. This includes PCB trace capacitance, MCU I/O pin capacitance, and any other devices on the bus. Use series resistors (≤ 1 kΩ) on SDA/SCL and minimize stub length to maintain signal integrity at full speed.

How does the WP pin function when left unconnected?

The WP pin has an internal pull-down resistor (~100 kΩ typical). When unconnected, it defaults to logic LOW (VSS), enabling full write access to all memory locations. To activate hardware write protection, WP must be externally tied to VDD; floating WP is functionally equivalent to WP = VSS.