M29W400FB55N3E - 4Mb NOR Flash 55ns TSOP-48 | Micron Technology
MPN: M29W400FB55N3E ✓ Active| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
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Drop-in alternatives for M29W400FB55N3E — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
M29W400FB55N3F
✅ Drop-In✓ In Stock
$2.55 / Unit
View Datasheet →M29F400FT55N3E2
✅ Drop-In✓ In Stock
$4.15 / Unit
View Datasheet →SST39VF402C-70-4I-EKE
✅ Drop-In📋 Reference alternative (not in catalog)
M29W320DB70N3E
✅ Drop-In✓ In Stock
$1.95 / Unit
View Datasheet →M29W400FB55N3E Maximum Ratings & Electrical Characteristics
| Memory Type | NOR Flash (parallel) |
| Density | 4 Mbit (4194 kbits) |
| Organization | 512K x 8 bit / 256K x 16 bit |
| Access Time | 55 ns |
| Supply Voltage (VCC) | 2.7 V to 3.6 V |
| Interface | Parallel, 8-bit/16-bit (BYTE# selectable) |
| Block Architecture | 19 memory blocks, 1 boot block (bottom, FB) |
| Programming Time | 10 us per byte/word typical |
| Boot Block Hardware Protection | Yes |
| Operating Temperature | -40C to +125C |
| Package | 48-TSOP I, 12 x 20 mm |
| Pins | 48 |
| Mounting Type | Surface Mount |
| Packaging | Tray |
| RoHS Status | Compliant |
| Speed Grades in Family | 55 ns, 70 ns |
M29W400FB55N3E 48-tsop i, 12 x 20 mm Pin Configuration Guide
Complete pinout information for M29W400FB55N3E (48-tsop i, 12 x 20 mm package) with 48 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 M29W400FB55N3E.
Refer to the datasheet for full pin configuration.
Estimated pin count: 48 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
M29W400FB55N3E is suitable for 6 applications: Embedded Boot Code Storage, Industrial PLC and Controller Firmware, Automotive Body and Powertrain Modules, Telecom Line Cards and Network Equipment, Set-Top Box and Consumer Electronics Boot ROM, Test and Measurement Instrument Firmware.
Embedded Boot Code Storage
The M29W400FB55N3E is a natural fit for boot-code storage because parallel NOR provides deterministic random access with a 55 ns access time, enabling execute-in-place firmware without copying code to RAM. The hardware-protectable bottom boot block safeguards the reset vector and first-stage bootloader from accidental erasure during field updates, while the remaining 18 blocks hold the main application image. On a 3.3 V microcontroller parallel bus, the device connects directly to a 2.7 V to 3.6 V VCC rail, and the BYTE# pin lets the same board support either an 8-bit 512K x 8 or a 16-bit 256K x 16 memory map. Designers should drive RP# from a supervised reset so the Flash never floats during brown-out.
Recommended
Industrial PLC and Controller Firmware
Programmable logic controllers and industrial control cards require firmware that survives power loss and field reprogramming over decades of service. The M29W400FB55N3E provides 4 Mbit of non-volatile storage with a -40C to +125C operating range that covers cabinet, motor-control, and outdoor installations. Its 19-block architecture lets engineers partition bootloader, application, and parameter storage into independent erase regions, so logging or calibration data can be updated without touching code blocks. The 10 us per byte/word typical programming time allows a full image update in well under a second over a service UART or fieldbus. Because the part is mature and widely second-sourced across distributors, long-term spare stocking is straightforward for industrial maintenance programs.
Recommended
Automotive Body and Powertrain Modules
Body control modules, instrument clusters, and powertrain auxiliaries use parallel NOR for code storage because it tolerates the harsh thermal and voltage environments typical of 12 V automotive systems with load-dump transients. The M29W400FB55N3E operates from -40C to +125C, matching under-hood and near-engine placement requirements, and its 2.7 V to 3.6 V supply connects directly to conditioned 3.3 V rails derived from automotive regulators. The boot block protection ensures that ECU boot firmware remains intact through mis-flashed updates or brown-out events during cranking. The FB bottom boot block convention matches legacy automotive memory maps, simplifying migration from earlier ST M29F designs without redrawing the code base.
Recommended
Telecom Line Cards and Network Equipment
Telecom line cards, WAN interface boards, and legacy network equipment have historically used 3 V parallel NOR for boot ROM and configuration storage, and the M29W400FB55N3E matches that convention exactly. Its 55 ns access time supports zero-wait-state or short-wait-state CPU boot from the parallel bus, keeping power-on self-test time short, while the 16-bit mode doubles effective bus throughput for code fetches compared to 8-bit wiring. The 19-block map allows the network-management parameter sector to be erased independently of the protocol firmware image. Because these platforms require long service life, the mature availability of this part across 14 distributor channels reported by Octopart makes it a practical sparing choice for maintenance fleets.
Recommended
Set-Top Box and Consumer Electronics Boot ROM
Set-top boxes, DVD players, and other consumer platforms frequently reserve a small parallel NOR device for the immutable boot loader while holding the main firmware in NAND or serial Flash. The M29W400FB55N3E suits this role with its low 4 Mbit cost point, 3.3 V single-supply operation, and protected boot block that guarantees the platform always reaches a recovery path. The BYTE# pin allows the same PCB to be populated for either 8-bit or 16-bit boot buses, reducing board variants across product families. Its RoHS-compliant TSOP-48 package with standard 1.27 mm pitch keeps assembly compatible with mainstream SMT lines. Consumer manufacturers typically stock the 70 ns grade for cost, reserving the 55 ns device for faster boot requirements.
Recommended
Test and Measurement Instrument Firmware
Bench instruments, data loggers, and modular test hardware need reliable non-volatile code storage with fast random reads to keep instrument startup latency low. The M29W400FB55N3E provides 4 Mbit of NOR with a 55 ns access time, directly addressable from the instrument microprocessor bus without serial protocol overhead. The 19-block sector map supports storing factory calibration constants in dedicated blocks that field firmware updates never erase, preserving traceability and accuracy data across service cycles. The -40C to +125C range and RoHS-compliant TSOP-48 package suit both laboratory and portable field instruments. Designers typically pair the device with a supervisor that holds RP# asserted until VCC is stable, ensuring the memory map is never misread during power ramp.
Recommended
Recommended Products Summary
Engineering reference data for M29W400FB55N3E — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | M29W400FB55N3F | M29F400FT55N3E2 | SST39VF402C-70-4I-EKE | M29W320DB70N3E |
|---|---|---|---|---|---|
| Brand | Micron Technology | Micron Technology | Micron Technology | Microchip Technology | Micron Technology |
| Package | 48-TSOP I (12 x 20 mm) | 48-TSOP I - same | 48-TSOP I - same | 48-TSOP I - same | 48-TSOP I - same |
| Density | 4 Mbit | 4 Mbit | 4 Mbit | 4 Mbit | 32 Mbit |
| Access Time | 55 ns | 55 ns | 55 ns | 70 ns | 70 ns |
| Supply Voltage | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V | 2.7 V to 3.6 V |
| Organization | 512K x 8 / 256K x 16 | 512K x 8 / 256K x 16 | 512K x 8 / 256K x 16 | 256K x 16 / 512K x 8 | 4M x 8 / 2M x 16 |
| Block Architecture | 19 blocks, bottom boot block | 19 blocks, bottom boot block | Asymmetric blocks, top boot block | Uniform sectors (SST architecture) | Bottom boot block, larger sector map |
| Operating Temperature | -40C to +125C | -40C to +125C | -40C to +125C | [DATA_NEEDED] | -40C to +85C |
| Programming Time | 10 us per byte/word typical | 10 us per byte/word typical | 10 us per byte/word typical | [DATA_NEEDED] | [DATA_NEEDED] |
Key Differentiators
- Fastest access time in its drop-in class (vs SST39VF402C-70-4I-EKE)
- Hardware-protectable boot block for safe field updates (vs SST39VF402C-70-4I-EKE)
- Direct firmware compatibility with legacy M29W fleet (vs M29F400FT55N3E2)
Design Notes
On 3.3 V parallel buses longer than about 10 cm or with multiple memory loads, add 22-33 ohm series termination resistors on address and data lines close to the driver to control ringing; at 55 ns access timing even 2-3 ns of overshoot-induced settle time erodes margin. Verify that the host bus interface timing budget accounts for the full 55 ns access plus output enable and data setup times, not just the address-to-data figure, especially in 8-bit BYTE# mode where cycle counts double for the same image size.
The RP# (reset/power-down) pin must never be left floating: if RP# is low during read attempts the device outputs invalid data, and a floating pin during power ramp can cause spurious block protection states. Tie RP# to the system supervisor reset through a 10 kohm pull-up. Similarly, BYTE# must be driven (or strapped) to a defined level at all times - it selects the 8-bit versus 16-bit bus mode, and an undriven BYTE# yields an undefined data width during boot.
Decouple VCC with 100 nF ceramic directly at the package plus a 4.7 uF bulk capacitor per device. Program and erase operations draw transient current pulses as the internal charge pump generates high voltage; insufficient bulk capacitance on a shared rail can inject supply droop into neighboring analog circuitry. Estimated: a full 4 Mbit erase plus reprogram at 10 us/byte takes roughly 5.2 seconds of pump activity per update cycle, so rail droop during in-system updates is a real, repeatable event worth measuring on the bench.
The 48-TSOP I (12 x 20 mm) footprint uses a 1.27 mm lead pitch; keep address lines length-matched within about 15 mm to each other to minimize skew in 16-bit mode, and route BYTE# and RP# as short, quiet traces away from switching clock nets. Because this part is commonly second-sourced against the SST39VF402C in the same footprint, leave the socket area clear of tall neighbors so either supplier's marking or a rework nozzle can access the package.
Compliance Information
RoHS compliance and lead-free finish indicated by distributor specification listings and the E suffix in the ordering code. REACH, halogen-free, and conflict minerals status not stated in provided data - verify on the Micron product page.
