16 Mbit SPI NOR flash for firmware storage and data logging
The AT45DB161E-SSHF-T is a 16 Mbit SPI NOR flash from Renesas' DataFlash family, organized as 528 bytes per page across 4096 pages. The 8-SOIC narrow-body package (3.90 mm width) keeps the PCB footprint small enough for space-constrained designs.
Page write and erase timing for firmware update planning
The write cycle time is 8 µs for a word and 4 ms for a full page. When budgeting a firmware-over-SPI update, the 4 ms per-page write time means a 256 KB image takes roughly 2 seconds of bus time, not counting the SPI transfer itself. The 85 MHz clock keeps the read side fast enough for execute-in-place (XIP) on controllers that support it. Memory organization as 528-byte pages (512 bytes data + 16 bytes spare) matches the DataFlash standard page size. The spare bytes are useful for ECC metadata or wear-leveling counters without consuming the main data area.
Renesas lists the AT45DB161E-SSHF-T as Active with ROHS3 compliance. The Tape & Reel packaging (also available as Cut Tape) suits automated pick-and-place assembly. The 8-SOIC body is MSL-rated per JEDEC — store the reels in a dry cabinet if the floor life is exceeded, standard practice for moisture-sensitive surface-mount packages.
Peer variants: page organization and packaging differences
Three peer variants share the same 16 Mbit density, 85 MHz SPI interface, and 8-SOIC package: the AT45DB161E-SSHFHA-T, AT45DB161E-SSHF2B-T, and AT45DB161E-SSHF-B. The key difference is memory organization — the -SSHFHA-T and -SSHF-B use 528-byte pages (same as this part), while the -SSHF2B-T uses 512-byte pages. The -SSHF-B ships in bulk tube rather than tape and reel. For a board designed around the 528-byte page organization, the -SSHF2B-T variant with 512-byte pages would require firmware changes to the page addressing logic. The -SSHFHA-T is a drop-in functional equivalent with the same page size and tape-and-reel packaging.