Infineon Technologies FM24W256-G

Overview

FM24W256-G from Infineon Technologies (formerly Cypress) is a 256-Kbit serial I²C F-RAM organized as 32K × 8, functioning as a nonvolatile memory replacement for EEPROM in microcontroller-based data logging and industrial control systems. It delivers NoDelay™ writes, 10¹⁴ read/write endurance, 151-year data retention at +85 °C, and operates across 2.7–5.5 V with I²C speeds up to 1 MHz.

For engineers reviewing the FM24W256-G datasheet, FM24W256-G pinout, FM24W256-G application, or FM24W256-G equivalent, key selection criteria include write-cycle frequency tolerance, I²C timing compatibility with legacy 100/400 kHz controllers, industrial temperature operation (–40 °C to +85 °C), and hardware-level drop-in replaceability for serial EEPROM without firmware changes.

Technical Context

The FM24W256-G implements a ferroelectric memory array accessed via standard I²C protocol with slave address 0xA0–0xA7 (7-bit base 0x50), supporting both random and sequential reads/writes. Its internal address latch auto-increments after each byte transfer, enabling burst operations without re-sending addresses.

Unlike EEPROM, it requires no internal charge pump: write operations complete synchronously at bus speed with zero polling delay, and consume only 100 µA active current at 100 kHz - eliminating voltage overhead and timing uncertainty inherent in EEPROM write cycles.

Key Specifications

Pinout & Package

FM24W256-G is housed in an 8-pin SOIC (Small Outline Integrated Circuit) package with standard 1.27 mm pitch, RoHS-compliant lead finish, and JEDEC MS-012AC outline dimensions.

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-G uniquely balances industrial temperature range, maximum endurance (10¹⁴), and guaranteed 1 MHz I²C support - making it optimal for high-frequency, mission-critical data capture where firmware simplicity and long-term reliability are jointly prioritized.

Availability

FM24W256-G is available at Aetrix Electronics and suitable for smart metering, PLC configuration storage, medical device event history, and automotive body control module designs requiring stable component supply across multi-year production lifecycles.

Supply support for FM24W256-G 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

Infineon Technologies is a global semiconductor leader headquartered in Munich, Germany, specializing in power management, sensing, connectivity, and security solutions for industrial, automotive, and IoT markets.

FM24W256-G belongs to Infineon's F-RAM product line, engineered specifically to replace EEPROM in high-write-frequency, low-power, and deterministic-timing applications - delivering nonvolatility without compromising RAM-like performance.

FAQ

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

Yes - FM24W256-G uses the same 8-pin SOIC package and identical pin functions (A0–A2, SDA, SCL, WP, VSS, VDD) as AT24C256-series EEPROMs. Its I²C slave address range (0xA0–0xA7) matches industry-standard EEPROM addressing, enabling direct hardware substitution without PCB redesign.

Does FM24W256-G require special I²C timing adjustments when replacing an EEPROM?

No - FM24W256-G supports standard I²C timing budgets for 100 kHz and 400 kHz modes, including setup/hold times and clock stretching behavior expected by legacy microcontrollers. Its 1 MHz capability is optional and backward-compatible.

How does the WP pin function, and what happens if it's left floating?

The WP pin is internally pulled down; leaving it unconnected defaults to write-enable mode. Tying WP to VDD activates hardware write protection across the full 32K address space. This is a hardwired safety feature independent of I²C commands or register settings.

Can FM24W256-G operate reliably during power supply brown-outs below 2.7 V?

No - FM24W256-G is specified for operation only between 2.7 V and 5.5 V. Below 2.7 V, data corruption may occur during active writes. System designers must implement brown-out detection and disable writes before VDD drops below this threshold to ensure data integrity.