Infineon Technologies FM1808B-SG

Overview

FM1808B-SG from Infineon Technologies (formerly Cypress) is a 256-Kbit (32 K × 8) parallel-interface ferroelectric RAM (F-RAM) with NoDelay™ writes, 10¹⁴ read/write endurance, and 151-year data retention. It functions as a nonvolatile drop-in replacement for SRAM in industrial data logging systems requiring rapid, frequent writes without battery backup.

For engineers reviewing the FM1808B-SG datasheet, FM1808B-SG pinout, FM1808B-SG application, or FM1808B-SG equivalent, key selection criteria include its 70-ns access time, 4.5–5.5 V operation, industrial temperature range (–40 °C to +85 °C), and compatibility with standard SRAM timing and address/data bus protocols.

Technical Context

The FM1808B-SG uses a ferroelectric memory array organized as 32,768 × 8 bytes, with all operations initiated by the falling edge of CE to latch address and trigger pre-charge. Unlike EEPROM or flash, it performs true byte-level writes at bus speed-no internal write cycles, no polling, and no delay between successive read/write operations.

Its control logic supports both CE-controlled and WE-controlled write modes, with identical 70-ns access time and 130-ns cycle time for reads and writes. The device requires CE strobing for every access to ensure row-level pre-charge and address latching-eliminating SRAM-style static CE usage but simplifying controller timing compared to legacy nonvolatile memories.

Key Specifications

Pinout & Package

FM1808B-SG is housed in a 28-pin Small Outline Integrated Circuit (SOIC) package with gull-wing leads, RoHS-compliant, and designed for reflow soldering on standard PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CY14B102QN-SXIT and IS61LV256AL-10TLI, FM1808B-SG uniquely delivers SRAM-equivalent timing *and* monolithic nonvolatility-removing battery management complexity while preserving existing parallel bus layouts and real-time write performance.

Availability

FM1808B-SG is available at Aetrix Electronics and suitable for industrial data loggers, smart meter firmware storage, and PLC I/O module configuration requiring stable component supply over extended production lifecycles.

Supply support for FM1808B-SG 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 systems, sensors, and memory solutions for industrial, automotive, and IoT applications.

The FM1808B-SG belongs to Infineon's F-RAM product line, engineered specifically to replace battery-backed SRAM and legacy EEPROM in high-write-frequency, mission-critical embedded systems where data integrity and longevity are non-negotiable.

FAQ

Is FM1808B-SG pin-compatible with standard 28-pin SOIC SRAMs like the IS61LV256AL?

Yes-FM1808B-SG uses an industry-standard 32 K × 8 parallel pinout with identical A0–A14, DQ0–DQ7, CE, WE, OE, VDD, and VSS assignments. However, CE must be actively strobed (not held low), and OE timing must respect the 70-ns access window. No PCB redesign is needed, but minor firmware timing adjustments may apply.

Does FM1808B-SG require external circuitry for data retention during power loss?

No-FM1808B-SG is inherently nonvolatile due to its ferroelectric memory cell structure. It retains data for 151 years at +85 °C without batteries, supercapacitors, or auxiliary power sources. System-level power sequencing only requires ensuring VDD stays within 4.5–5.5 V during active operation.

What is the significance of the "pre-charge operation" in FM1808B-SG timing?

The pre-charge operation is an internal reset phase triggered when CE rises HIGH. It prepares the memory array for the next access and enforces minimum timing margins. Unlike SRAM, FM1808B-SG mandates this phase-requiring CE to go HIGH between cycles. This ensures reliable row activation and eliminates cumulative timing drift across temperature and voltage.

Can FM1808B-SG be used in place of EEPROM for firmware storage in microcontroller boot loaders?

Yes-but only where byte-level random writes and fast update rates are prioritized over absolute density efficiency. FM1808B-SG supports unlimited writes at bus speed, making it ideal for dynamic configuration storage or runtime parameter logging. For pure firmware image storage (infrequent large-block writes), serial NOR flash may offer higher density at lower cost.