Infineon Technologies FM25CL64B-G

Overview

FM25CL64B-G from Infineon Technologies (formerly Cypress) is a 64-Kbit serial SPI F-RAM organized as 8K × 8, functioning as a nonvolatile memory replacement for EEPROM and serial flash in real-time data logging systems. It delivers NoDelay™ writes at up to 20 MHz SPI clock rate, supports industrial temperature (–40 °C to +85 °C), operates from 2.7 V to 3.65 V, and guarantees 10¹⁴ read/write cycles with 151-year data retention.

For engineers reviewing the FM25CL64B-G datasheet, FM25CL64B-G pinout, FM25CL64B-G application, or FM25CL64B-G equivalent, key selection criteria include write endurance, zero-write-latency operation, SPI mode 0/3 compatibility, hardware/software write protection, and dual-package availability (SOIC-8 and DFN-8) for space-constrained industrial control and metering designs.

Technical Context

The FM25CL64B-G implements ferroelectric memory technology enabling true RAM-like write behavior without erase cycles or polling. Its internal architecture includes an 8K × 8 F-RAM array, 3-bit address masking (13-bit effective addressing), and on-die status register with WPEN-controlled hardware write protection via the WP pin.

It operates as a standard SPI slave supporting modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1), with all inputs latched on SCK rising edge and SO outputs driven on falling edge. The HOLD pin enables transaction suspension without clock or CS timing constraints, provided transitions occur while SCK is LOW.

Key Specifications

Pinout & Package

FM25CL64B-G is available in two RoHS-compliant packages: 8-pin SOIC (width 3.9 mm) and 8-pin DFN (3 mm × 3 mm, exposed pad not connected). Both share identical pin functions and logic-level compatibility.

Key Features

Applications

Equivalent & Alternatives

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

Compared with MB85RS64V and AT25DF041A, FM25CL64B-G uniquely combines deterministic zero-latency writes, hardware HOLD/WP, and industrial-temp reliability in a drop-in SPI footprint - making it optimal for safety-critical, high-cycle embedded logging where timing predictability is mandatory.

Availability

FM25CL64B-G is available at Aetrix Electronics and suitable for smart metering, industrial PLC data logging, medical diagnostic storage, and automotive telematics event buffering requiring stable component supply across extended product lifecycles.

Supply support for FM25CL64B-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, and connectivity solutions for industrial, automotive, and IoT applications.

The FM25CL64B-G belongs to Infineon's F-RAM portfolio - engineered specifically for deterministic, high-endurance nonvolatile storage in systems where flash or EEPROM latency, wear-out, or power-loss corruption pose functional safety risks.

FAQ

Is FM25CL64B-G pin-compatible with standard SPI EEPROMs like AT25xxx series?

Yes - FM25CL64B-G uses identical 8-pin SOIC/DFN footprints and SPI command set (WREN, WRDI, RDSR, WRSR, READ, WRITE) as AT25xxx EEPROMs. Addressing, opcode timing, and CS/SCK/SI/SO signal behavior match exactly, enabling direct hardware replacement without PCB revision.

Does FM25CL64B-G require external high-voltage programming circuitry?

No - FM25CL64B-G performs all writes at standard VDD levels (2.7–3.65 V) with no charge pump or elevated voltage generation. Unlike EEPROM or flash, it requires no external VPP pin or programming voltage sequencing, simplifying power design and reducing BOM count.

Can the HOLD pin be left unconnected in a simple single-master system?

No - the HOLD pin must be tied to VDD if unused, per datasheet requirement. Leaving it floating may cause unintended transaction suspension due to noise coupling, leading to corrupted reads/writes or bus lockup during high-noise industrial operation.

What happens to data during a power interruption mid-write?

Data remains intact - FM25CL64B-G writes are atomic at the byte level and require no erase cycle. A power loss during a write operation affects only the byte currently being shifted in; prior bytes retain valid data, and no block-level corruption occurs as with flash memory.