Infineon Technologies FM18W08-SG

Overview

FM18W08-SG from Cypress Semiconductor 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 operates across 2.7 V to 5.5 V, supports industrial temperature (–40 °C to +85 °C), and replaces SRAM/EEPROM in nonvolatile logging, metering, and event capture systems where rapid, frequent writes are required.

For engineers reviewing the FM18W08-SG datasheet, FM18W08-SG pinout, FM18W08-SG application, or FM18W08-SG equivalent, key selection criteria include write-cycle timing equivalence to SRAM, CE-controlled address latching, pre-charge requirement on CE high, absence of write polling, and compatibility with standard 28-pin SOIC footprint and 32 K × 8 memory mapping.

Technical Context

The FM18W08-SG implements a bytewide parallel interface with 15 address lines (A14–A0) and 8 bidirectional data lines (DQ7–DQ0), requiring CE falling edge to latch address and initiate all memory cycles. Unlike SRAM, it mandates CE HIGH for internal pre-charge between accesses, enforcing minimum t_PC (pre-charge time).

Its F-RAM core enables true nonvolatility without backup batteries or write delays: data becomes persistent at bus speed, with identical 70 ns access time and 130 ns cycle time for reads and writes. Endurance is row-based (64-bit rows), with each 8-byte boundary marking a new row.

Key Specifications

Pinout & Package

FM18W08-SG is housed in a 28-pin Small Outline Integrated Circuit (SOIC) package, surface-mount compatible with JEDEC MS-012AC outline, 300 mil width, and RoHS-compliant finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with IS61LV256AL-10TLI and AT28HC256-90PU, FM18W08-SG delivers true monolithic nonvolatility with SRAM-equivalent timing and 10⁹× higher endurance - eliminating backup components, write latency, and firmware complexity in high-frequency logging applications.

Availability

FM18W08-SG is available at Aetrix Electronics and suitable for smart energy metering, industrial PLC data logging, and automotive body control modules requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for FM18W08-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

Cypress Semiconductor (now part of Infineon Technologies) designs high-reliability memory and microcontroller solutions for industrial, automotive, and IoT applications, with emphasis on low-power, robust nonvolatile technologies.

The FM18W08-SG belongs to Cypress's F-RAM product line, engineered specifically to replace battery-backed SRAM and slow EEPROM in systems demanding rapid, unlimited, and deterministic nonvolatile writes.

FAQ

Is FM18W08-SG pin-compatible with standard 32 K × 8 SRAMs like the IS61LV256AL?

Yes - FM18W08-SG uses an industry-standard 28-pin SOIC package with identical pinout for A14–A0, DQ7–DQ0, CE, OE, WE, VDD, and VSS. However, CE must strobe (fall on each access) rather than remain static, and pre-charge requires CE HIGH between cycles - minor controller timing adjustments may be needed.

Does FM18W08-SG require external hardware for nonvolatility, such as a battery or capacitor?

No - FM18W08-SG is monolithic nonvolatile memory using ferroelectric technology. It retains data without any external components, eliminating battery leakage, capacitor aging, and associated reliability concerns inherent in battery-backed SRAM modules.

What happens if CE remains LOW beyond the maximum specified duration?

Exceeding t_CEMAX (maximum CE LOW time) risks data corruption or undefined behavior because internal pre-charge cannot occur. The device requires CE HIGH for ≥t_PC (minimum pre-charge time) before the next falling edge - this must be enforced in controller firmware or logic timing design.

Can FM18W08-SG operate reliably during power supply brownouts between 2.7 V and 3.0 V?

Yes - FM18W08-SG is fully specified down to 2.7 V across the full industrial temperature range. Unlike battery-backed SRAM, it does not block access or enter protection mode at low VDD; however, the host MCU must ensure CE and WE remain HIGH during brownout to prevent partial writes.