256 Mbit SPI NOR in a compact 8-WSON
The S25FS256SAGNFI001 is a 256 Mbit SPI NOR flash from Infineon's FS-S series, organized as 32M x 8 bits. It communicates over a SPI bus with Quad I/O and QPI support, clocking up to 133 MHz — enough to feed a Cortex-M or RISC-V core a boot image or firmware update without stalling the bus.
Supply and temperature fit
The supply range is 1.7 V to 2.0 V, which maps cleanly to a 1.8 V rail — the same rail that powers many MCU I/O banks and DDR memory interfaces. The part draws its operating current from this rail; the peak during a page program or sector erase is higher than the standby figure, so the regulator should be sized for the transient, not the average.
Package and board integration
The datasheet's recommended footprint includes a central ground pad with thermal vias — skipping those vias raises the junction-to-board thermal resistance and limits the write duty cycle before the part throttles. The part is surface-mount and supplied in a Tube. For reflow, the MSL rating should be confirmed from the lot date code; typical WSON packages are MSL-3, meaning a 168-hour floor life after bake before the moisture barrier is exhausted.