M29F400FB55M3F2 - 4Mbit 5V NOR Flash 55ns | Micron
MPN: M29F400FB55M3F2 β Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.46 | $2.46 |
| 10 | $2.21 | $22.10 |
| 100 | $1.98 | $198.00 |
| 500 | $1.85 | $925.00 |
| 1,000 | $1.72 | $1,720.00 |
Drop-in alternatives for M29F400FB55M3F2 β same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool β Select alternative parts for side-by-side comparison:
M29F400FB55M3T2
β Drop-Inπ Reference alternative (not in catalog)
M29F400BB70M6T
β Drop-Inπ Reference alternative (not in catalog)
M29F400FB55M3F2
β Drop-Inβ In Stock
$1.72 / Unit
View Datasheet βM29F400FB55M3F2 TR
β Drop-Inπ Reference alternative (not in catalog)
M29F400FB55M3F2 Maximum Ratings & Electrical Characteristics
| Memory Type | NOR Flash, Parallel |
| Density | 4194 kbits (4 Mbit) |
| Organization | 512K x 8 / 256K x 16 |
| Access Time | 55 ns |
| Supply Voltage (VCC) | 5 V |
| Boot Block Position | Bottom boot block |
| Operating Temperature | -40C to +125C |
| Grade | Automotive (Auto Grade, 125C) |
| Package Type | 44-pin SO (SOP), wide body |
| Mounting Type | Surface Mount |
| Programming | Embedded byte/word program algorithm |
| Erase | Embedded program/erase controller, block erase |
| Packaging | Tape and Reel (TR) |
| RoHS Status | RoHS-compliant package (F2 suffix) |
| Bus Width | 8-bit or 16-bit (selectable) |
| Number of Pins | 44 |
M29F400FB55M3F2 44-pin so (sop), wide body Pin Configuration Guide
Complete pinout information for M29F400FB55M3F2 (44-pin so (sop), wide body package) with 44 pins. This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for M29F400FB55M3F2.
Refer to the datasheet for full pin configuration.
Estimated pin count: 44 pins (digital package)
Safe Operating Area (SOA) & Thermal Characteristics
No official SOA curve available for this digital IC. Always operate within absolute maximum ratings specified in the datasheet. Ensure adequate cooling and derate as needed.
Typical Applications
M29F400FB55M3F2 is suitable for 6 applications: Automotive ECU Boot Code Storage, Industrial Control and PLC Firmware, Telecom Line Cards and Network Modules, Set-Top Box and Consumer Electronics Boot Memory, Test and Measurement Instrument Firmware, Second-Source and EOL Mitigation Designs.
Automotive ECU Boot Code Storage
The M29F400FB55M3F2 fits automotive ECU boot storage because it combines -40C to +125C automotive-grade operation with a bottom boot block that holds reset vectors and bootloader code at the bottom of the address map, exactly where many MCUs fetch their first instructions. Its 55 ns access time allows in-place execution on 5 V processor buses without shadow RAM, and the embedded program/erase controller lets firmware field-update calibration blocks safely while block protection guards the boot sector. Placed directly on the MCU's multiplexed address/data bus with a single 5 V supply, it needs no level shifting or charge pump - a key advantage over 3 V serial Flash in legacy 5 V automotive platforms.
Recommended
Industrial Control and PLC Firmware
Industrial controllers benefit from the M29F400FB55M3F2's combination of 4 Mbit density - enough for a full control firmware image plus parameters - and its 5 V I/O, which interfaces directly with legacy industrial 5 V logic families common in PLC I/O racks. The 55 ns random access supports XIP execution of the control loop code, avoiding RAM copying and its associated boot delay. The wide -40C to +125C temperature rating covers unconditioned cabinets and motor-adjacent installations. Embedded byte/word program algorithms make field firmware updates deterministic, while block protection can lock the bootloader against accidental erasure during parameter rewrites.
Recommended
Telecom Line Cards and Network Modules
Telecom line cards historically standardized on 5 V parallel NOR for code storage, and the M29F400FB55M3F2 matches that environment precisely: a single 5 V supply, 5 V-tolerant parallel bus, and 44-pin SO footprint that drops into existing line-card layouts. The 55 ns access time serves the network processor's boot fetches, and the 256K x 16 organization matches 16-bit backplane bus widths. Bottom boot block placement keeps the reset vector region separate from application and configuration blocks, enabling safe in-field software image updates on deployed telecom hardware while the boot block remains protected.
Recommended
Set-Top Box and Consumer Electronics Boot Memory
Set-top boxes and consumer AV platforms use the M29F400FB55M3F2 to hold the initial bootloader and configuration data: the 4 Mbit capacity stores a compact boot loader, while the 55 ns parallel access gives the SoC immediate executable code at power-up before DRAM initialization completes. The 5 V supply suits power-supply domains in these boards, and the wide-body SO package reflows on standard assembly lines. Automotive temperature rating exceeds consumer requirements, providing extra margin against enclosure heat. Embedded erase algorithms allow the OS updater to refresh configuration blocks during software updates without custom erase timing code.
Recommended
Test and Measurement Instrument Firmware
Bench instruments and data acquisition systems use the M29F400FB55M3F2 to store firmware, calibration constants, and instrument settings. The 55 ns XIP-capable access lets the main CPU run startup diagnostics directly from Flash, and the 5 V bus simplifies integration with older 5 V microcontroller subsystems still common in instrumentation. The -40C to +125C rating tolerates rack-mounted thermal environments and portable field units alike. Calibration tables stored in main blocks can be rewritten during factory recalibration while block protection keeps the executive firmware image immutable, protecting traceability and instrument accuracy certification.
Recommended
Second-Source and EOL Mitigation Designs
Because Micron's parallel NOR line faces consolidation, designs increasingly dual-source boot memory. The M29F400FB55M3F2 is actively replicated by Alliance Memory as a pin-for-pin drop-in in the same SOP 44-pin package with identical 4 Mbit, 55 ns, 5 V, bottom boot, and -40C to +125C ratings. Designing the footprint for the 44-pin wide SO allows engineers to qualify both sources on one PCB, cutting lead-time risk from weeks to days and avoiding redesigns when one vendor allocates. Command-set compatibility means a single firmware driver programs both sources without code changes.
Recommended
Recommended Products Summary
Engineering reference data for M29F400FB55M3F2 β comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | M29F400FB55M3T2 | M29F400BB70M6T | M29F400FB55M3F2 (Alliance Memory) |
|---|---|---|---|---|
| Package | 44-SO (SOP) wide body | 44-SO (SOP) - same | 44-SO (SOP) - same | SOP 44-pin - same |
| Brand | Micron Technology | Micron Technology | Micron Technology | Alliance Memory |
| Density | 4 Mbit (512K x8 / 256K x16) | 4 Mbit | 4 Mbit | 4 Mbit |
| Access Time | 55 ns | 55 ns | 70 ns | 55 ns |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V |
| Boot Block | Bottom | [DATA_NEEDED] | Bottom | Bottom |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | -40C to +125C |
| Price (qty 1, as of 2026-09-05) | ~$2.46 | [DATA_NEEDED] | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- 55 ns access time enables zero-wait-state XIP (vs M29F400BB70M6T)
- True automotive 125C grade (vs M29F400FB55M3T2)
- Dual-source availability without redesign (vs M29F400FB55M3F2 (Alliance Memory))
Design Notes
The M29F400FB55M3F2 operates from a single 5 V VCC for read, program, and erase - no separate 12 V programming supply is required, unlike older UV-EPROM-style Flash. Decouple VCC with at least 0.1 uF ceramic at each supply pin plus 10 uF bulk near the device, because program/erase currents arrive as short high-amplitude pulses that can droop a weak rail and corrupt adjacent programming operations. Estimated: at typical 5 V logic rail tolerances (+/-5%), keep VCC above 4.75 V during erase to stay within datasheet operating conditions.
The 44-pin wide-body SO package requires the wide SOIC land pattern (0.5 inch body span); verify your footprint against the datasheet mechanical drawing before layout reuse from TSOP footprints. Keep the address/data bus traces of matched length where possible, and avoid routing the BYTE strap pin near switching clock lines - a glitch on BYTE mid-cycle can reconfigure bus width between reads. Tie unused control inputs (e.g., RP/BUSY handling per family datasheet) to defined logic levels, never leave floating.
Verify boot block position before substitution: the FB (bottom boot) version must be matched with bottom boot equivalents when the processor fetches reset vectors from address 0. The BB70M6T variant is pin-compatible but 70 ns - confirm your bus timing still closes with margin. Additionally, the M29F400 family command set differs from CFI-only parts; reuse of firmware drivers from AMD 29F400 designs is generally compatible but should be validated against the Micron datasheet command definitions before production.
Compliance Information
RoHS compliance and lead-free status derived from the F2 suffix (RoHS-compliant package) per Micron part numbering. REACH, AEC-Q100, halogen-free, and conflict-minerals status should be confirmed via official Micron compliance certificates on the product detail page.
