128 Mbit NOR flash on a 1.7-2 V rail
The S25FS128SAGMFI103 is a 128 Mbit NOR flash from Infineon's FS-S series, organized as 16M x 8 bits. It runs on a 1.7 V to 2 V supply — that narrow window means you cannot drop it onto a 3.3 V SPI bus without a regulator, but it also keeps the active power low in a battery-backed design. The SPI interface supports Quad I/O and QPI modes at up to 133 MHz, which pushes the effective read throughput well past what a single-bit SPI line can manage — useful for shadowing code to RAM on boot or streaming calibration tables.
Industrial temperature and SOIC footprint
Available cut tape or tape-and-reel, which is the usual story for pick-and-place assembly. The SOIC-8 lands on a standard 1.27 mm pitch footprint, so the board layout is straightforward and the decoupling cap sits close to the supply pin without a fight.
Active lifecycle and compliance baseline
That means you can design it into a new BOM today without planning a migration path. The FS-S series is Infineon's current-generation SPI NOR family, so firmware tools and driver support are well-established across MCU ecosystems. No second-source or pin-compatible alternative is recorded on this listing — it is a single-source line, which is normal for a proprietary memory controller interface.