Infineon Technologies FM25H20-G

Overview

FM25H20-G from Infineon Technologies (formerly Cypress) is a 2-Mbit serial SPI F-RAM memory organized as 256 K × 8, featuring NoDelay™ writes, 10¹⁴ read/write endurance, 151-year data retention, 40-MHz SPI interface, and industrial-grade operation from –40 °C to +85 °C - deployed in real-time data logging, metering, and industrial control systems where rapid nonvolatile writes are critical.

For engineers reviewing the FM25H20-G datasheet, FM25H20-G pinout, FM25H20-G application, or FM25H20-G equivalent, key selection criteria include write latency (zero-cycle), endurance margin vs. EEPROM/flash, SPI mode 0/3 compatibility, hardware/software write protection granularity, and low-power sleep mode (3 µA) for battery-backed systems.

Technical Context

The FM25H20-G implements ferroelectric memory cells enabling true RAM-like random access with nonvolatile retention - eliminating erase cycles and polling delays inherent in flash/EEPROM. Its internal logic includes an 18-bit address counter, 3-bit status register with WPEN bit, and opcode decoder supporting WREN, WRDI, RDSR, WRSR, READ, WRITE, and HOLD commands.

It operates as a full-duplex SPI slave in Mode 0 (CPOL = 0, CPHA = 0) and Mode 3 (CPOL = 1, CPHA = 1), with SI latched on rising SCK edge and SO driven on falling edge. The HOLD pin suspends ongoing transfers without clock or CS dependency, provided transitions occur while SCK is LOW.

Key Specifications

Pinout & Package

FM25H20-G is available in two RoHS-compliant packages: 8-pin SOIC (width 3.9 mm) and 8-pin TDFN (3 mm × 3 mm, 0.5 mm pitch). Both packages feature identical pin functions and electrical characteristics.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY14B102QN-SP and AT25SF041-SSHD-B, FM25H20-G uniquely delivers zero-write-latency, 10¹⁴-cycle endurance, and 151-year retention in an 8-pin SPI package - making it the sole option for deterministic real-time nonvolatile logging without firmware complexity.

Availability

FM25H20-G is available at Aetrix Electronics and suitable for smart metering, industrial PLCs, medical wearables, and automotive telematics requiring stable component supply across extended product lifecycles.

Supply support for FM25H20-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, delivering power management, sensing, connectivity, and memory solutions for industrial, automotive, and IoT applications.

The FM25H20-G belongs to Infineon's F-RAM portfolio - engineered specifically for applications demanding infinite write endurance, instant nonvolatile storage, and ultra-low power - replacing legacy serial flash and EEPROM where timing determinism and reliability are non-negotiable.

FAQ

Is FM25H20-G pin-compatible with standard SPI EEPROMs like AT25XXX series?

Yes - FM25H20-G uses identical 8-pin SOIC/TDFN footprints and matches the standard SPI pinout (CS, SCK, SI, SO, WP, HOLD, VDD, VSS). It accepts the same opcodes for READ and WRITE, and supports SPI modes 0 and 3. No PCB redesign is needed for drop-in replacement, though firmware must disable EEPROM-specific polling loops due to NoDelay™ writes.

Does FM25H20-G require external high-voltage programming or special write sequences?

No - FM25H20-G performs writes at standard VDD (2.7–3.6 V) with no charge pump or high-voltage generator. A single SPI WRITE command followed by data bytes completes the operation. Unlike flash or EEPROM, there is no erase step, no write-enable delay, and no status polling - data is committed immediately after the final clock edge of each byte.

How does the HOLD function interact with ongoing write operations?

When HOLD is asserted LOW during a write, the FM25H20-G freezes the internal address counter and data latch state, suspending the transfer without corruption. SCK and CS are ignored until HOLD returns HIGH while SCK is LOW. Upon resumption, the device continues from the exact byte position - preserving atomicity for multi-byte writes across CPU interrupts or priority tasks.

What is the impact of tying WP HIGH versus leaving it floating?

WP must be tied to VDD (not left floating) to ensure predictable behavior. If left unconnected, noise or leakage may cause intermittent low states, unintentionally locking the Status Register and blocking future write protection changes. Tying WP to VDD disables hardware write protection, allowing full software control via WRSR - the recommended configuration unless permanent hardware lock is required.