Micron Technology

M29F400FB55M3F2

A: Thanks to its 4 Mbit capacity, 55 ns fast access time, automotive‑grade operating temperature range (−40°C to +125°C), and AEC‑Q100 qualification, the M29F400FB55M3F2 was well‑suited for a broad range of applications, including: Automotive electronics – Engine control units (ECUs), body control modules, advanced driver‑assistance systems (ADAS), infotainment systems, and navigation units Industrial control systems – PLCs, human‑machine interfaces (HMIs), industrial automation controllers, and robotics Consumer appliances – Set‑top boxes, smart home appliances, and digital TV equipment Telecommunications and networking equipment – Routers, switches, and base stations Medical devices – Diagnostic equipment and patient monitoring systems ⚠️ Important Lifecycle Information: The M29F400FB55M3F2 has been designated Obsolete by the original manufacturer (Micron Technology). The Micron Obsolete Part Catalog explicitly lists the Part Status Code as Obsolete and the product is no longer in active production. Multiple distributor sources confirm this status. However, there are conflicting lifecycle reports: some distributor databases still list the product as Active with a product lifecycle code of “在产” (In Production) or Active in volume production, while other sources from the same distributor categorise the device as Obsolete. Given these conflicting reports, the most authoritative source (Micron Obsolete Part Catalog) confirms the device is Obsolete. Replacement / Alternative Options: The M29F400FB55M3E2 (SOIC‑44 package, Tray packaging) is listed as a fully compatible drop‑in replacement, offering identical electrical specifications and pin compatibility. DigiKey also lists this variant as Active. The M29F400FB55M3T2 (SOIC‑44 package, Tape & Reel) provides the same electrical specifications but may have minor physical form‑factor differences; DigiKey also lists this variant as Active. For new designs requiring long‑term supply assurance, engineers are strongly advised to select currently active parallel NOR Flash devices from the M29F400 series (such as the Tray‑packaged “E2” variant) or evaluate migration to newer 5V parallel NOR Flash families from Micron (such as the M29W series with lower power consumption) that remain in active production. However, customers should note that the entire M29F400 product family is aging and overall production may be limited. Given the conflicting lifecycle reports, engineers are strongly advised to verify current lifecycle status, availability, and lead times directly with an authorised Micron or Alliance Memory distributor before committing this part to a new design. For legacy systems already using this part, remaining inventory may be available through specialist distributors for sustaining production, but long‑term supply should not be assumed.