Infineon Technologies FM25L04B-GTR

Overview

FM25L04B-GTR from Infineon Technologies (formerly Cypress) is a 4-Kbit serial SPI F-RAM organized as 512 × 8, featuring NoDelay™ writes, 10¹⁴ read/write endurance, and 151-year data retention. It operates at up to 20 MHz SPI clock, supports modes 0 and 3, and functions as a hardware drop-in replacement for serial EEPROM or flash in industrial sensor logging and real-time control systems.

For engineers reviewing the FM25L04B-GTR datasheet, FM25L04B-GTR pinout, FM25L04B-GTR application, or FM25L04B-GTR equivalent, key selection criteria include write-cycle speed without polling, low active current (200 µA @ 1 MHz), industrial temperature range (–40 °C to +85 °C), and dual-package availability (SOIC-8 and DFN-8).

Technical Context

The FM25L04B-GTR implements a ferroelectric memory array with zero write latency - data commits immediately after each byte transfer, eliminating wait states and polling. Its internal architecture includes a dedicated instruction decoder, address counter, and nonvolatile status register with configurable block protection.

SPI interface logic supports full-duplex communication at up to 20 MHz with strict timing alignment: inputs latched on SCK rising edge, outputs driven on falling edge. Write protection is enforced via both hardware (WP pin) and software (WRSR-controlled block lock), enabling selective 1/4, 1/2, or full-array write disable.

Key Specifications

Pinout & Package

FM25L04B-GTR is available in two RoHS-compliant packages: 8-pin SOIC (3.9 mm × 4.9 mm) and 8-pin DFN (2 mm × 3 mm) with exposed pad (unconnected). Both packages share identical pin functions and electrical behavior.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MB85RS4MT-FPNSE1 and AT25SF041-SSHD-B, FM25L04B-GTR delivers unmatched write endurance and latency-critical determinism at 4 Kbit scale - making it the sole choice where sub-millisecond write atomicity and billion-cycle reliability are mandatory.

Availability

FM25L04B-GTR is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical sensor nodes, and automotive body control units requiring stable component supply across multi-year production cycles.

Supply support for FM25L04B-GTR 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, delivering power systems, microcontrollers, sensors, and memory solutions for industrial, automotive, and IoT applications.

The FM25L04B-GTR belongs to Infineon's F-RAM portfolio - engineered specifically for applications demanding frequent, deterministic, low-power nonvolatile writes without endurance limitations or write latency penalties.

FAQ

What is the maximum SPI clock frequency supported by FM25L04B-GTR?

The FM25L04B-GTR supports SPI clock frequencies up to 20 MHz across its full operating temperature range (–40 °C to +85 °C). This is verified per AC switching characteristics in the official datasheet (Rev. *K, page 13), with setup/hold times met at 20 MHz under worst-case VDD and temperature conditions.

Does FM25L04B-GTR require a write-enable command before every write operation?

Yes - the WREN (Write Enable) instruction must be issued and confirmed via RDSR before any WRITE or WRSR command. The Write Enable Latch (WEL) bit remains set until cleared by WRDI or power-on reset, but errata note that WEL does not auto-clear after writes to addresses 0x100–0x1FF (page 20).

Can the HOLD pin be used during a write operation without corrupting data?

Yes - the HOLD pin suspends ongoing operations safely when asserted LOW while SCK is LOW. The device retains internal state and resumes exactly where interrupted upon HOLD deassertion; no data corruption occurs, and no retransmission is needed.

Is the EXPOSED PAD on the DFN package electrically connected?

No - the EXPOSED PAD on the 8-pin DFN package is not connected to the die or any internal circuitry. Per datasheet page 17, it must remain unconnected and unsoldered on the PCB to prevent mechanical stress or unintended thermal coupling.