It stores 16M x 8 bits in a non-volatile FLASH array and communicates over SPI with Quad I/O and QPI protocol support. The 8-WSON package with exposed pad (5x6 mm body) keeps the footprint small while the pad sinks heat from sustained reads.
133 MHz Quad-SPI — throughput and bus margin
At 133 MHz in Quad I/O mode, each pin carries data at 133 Mbps, giving an aggregate 532 Mbps read bandwidth on a four-bit bus. That is enough to feed a 32-bit Cortex-M or RISC-V core running at moderate clock speeds without wait-state stalls — provided the host controller supports Quad-SPI at that frequency. The QPI mode (Quad Peripheral Interface) extends the quad-wide protocol to commands and addresses, not just data, which cuts command overhead on random-access patterns.
AEC-Q100 and 125°C — the automotive bill-of-material fit
The AEC-Q100 qualification (Automotive, FL-L series) is the differentiator that puts this part on tier-1 ECU BOMs. The industrial-temperature siblings S25FL128LAGNFI010 and S25FL128LAGMFA000 are rated to 85°C only — they will not survive a hot-soak under the hood. For dual-sourcing, the S25FL128SAGBHM200 from the FL-S series is also AEC-Q100 qualified and rated to 125°C, though it lacks QPI mode — verify your firmware driver supports the FL-S command set before substituting.
8-WSON footprint and thermal pad — layout notes
The exposed pad is also the ground return for the die, so it must be soldered to the PCB ground plane — not left floating.