Infineon Technologies FM25L04B-GATR

Overview

FM25L04B-GATR from Cypress Semiconductor is an automotive-grade 4-Kbit (512 × 8) serial SPI ferroelectric RAM (F-RAM) with NoDelay™ write capability, 10¹³ read/write endurance, and AEC-Q100 Grade 1 qualification (–40 °C to +125 °C). It operates at up to 10 MHz SPI clock, supports modes 0 and 3, and delivers immediate byte-write completion without polling-ideal for real-time data logging in engine control units and battery management systems.

For engineers reviewing the FM25L04B-GATR datasheet, FM25L04B-GATR pinout, FM25L04B-GATR application, or FM25L04B-GATR equivalent, key selection criteria include guaranteed automotive temperature operation, hardware/software write protection, zero-latency writes, and direct SPI drop-in compatibility with serial EEPROM and flash in safety-critical embedded systems.

Technical Context

The FM25L04B-GATR implements a synchronous SPI slave interface with dual-mode support (0 and 3), where inputs are latched on the rising SCK edge and outputs driven on the falling edge. Its internal architecture integrates a 512 × 8 F-RAM array, nonvolatile status register, and dedicated control logic for opcode decoding, address counting, and write-enable latch management.

Write operations execute atomically at bus speed-no internal write cycle delay-and are confirmed by status register WIP bit clearing immediately after byte transfer. The device lacks internal power management beyond POR, requiring strict VDD regulation (3.0–3.6 V) and external handling of chip-select sequencing and HOLD timing constraints.

Key Specifications

Pinout & Package

FM25L04B-GATR is housed in an 8-pin small outline integrated circuit (SOIC) package with gull-wing leads, RoHS-compliant finish, and JEDEC MS-012AC footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MB85RS4MT-FPNSE and AT25DF041A-SHB-T, FM25L04B-GATR uniquely balances automotive qualification, ultra-high endurance, and true zero-latency writes at minimal density-making it optimal for safety-critical parameter storage where reliability outweighs capacity or raw speed.

Availability

FM25L04B-GATR is available at Aetrix Electronics and suitable for engine control units, battery management systems, advanced driver assistance systems, and electronic power steering modules requiring stable component supply across extended automotive production lifecycles.

Supply support for FM25L04B-GATR 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 semiconductor solutions for automotive, industrial, and IoT applications, with emphasis on embedded memory and programmable systems.

FM25L04B-GATR belongs to Cypress's automotive F-RAM product line, engineered specifically to replace serial EEPROM and flash in safety-critical systems demanding deterministic write performance and long-term data integrity.

FAQ

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

The FM25L04B-GATR supports SPI clock frequencies up to 10 MHz across its full automotive temperature range (–40 °C to +125 °C), with timing validated per AC switching characteristics in Rev. *E datasheet. Operation above 10 MHz is not characterized and may result in data corruption or command rejection.

How does the HOLD pin function during an active memory operation?

When HOLD is pulled LOW while SCK is LOW, the FM25L04B-GATR suspends the current read or write operation, ignores subsequent SCK and CS transitions, and maintains SO in tristate. The operation resumes automatically upon the next CS falling edge, with no data loss or status corruption.

Is FM25L04B-GATR pin-compatible with standard SPI EEPROMs like AT25040?

Yes-FM25L04B-GATR uses identical 8-pin SOIC packaging and matches the pinout (CS, SCK, SI, SO, WP, HOLD, VSS, VDD) of industry-standard SPI EEPROMs. It accepts the same opcodes (0x02, 0x03, 0x06, 0x04) and requires no PCB redesign for drop-in replacement.

Does FM25L04B-GATR require external high-voltage programming circuitry?

No-FM25L04B-GATR performs all writes at standard VDD (3.0–3.6 V) with no external voltage pumps or programming pulses. Its ferroelectric memory cells switch polarization states using normal I/O signaling, eliminating HV generators, charge pumps, and associated reliability concerns.