MX29F400CBTI-70G - 4Mbit 5V Parallel NOR Flash, 70ns, 48-TSOP | Macronix
MPN: MX29F400CBTI-70G ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.85 | $2.85 |
| 10 | $2.55 | $25.50 |
| 100 | $2.15 | $215.00 |
| 500 | $1.85 | $925.00 |
| 1,000 | $1.62 | $1,620.00 |
MX29F400CBTI-70G Overview
A NOR Flash memory is a non-volatile storage class that executes code directly from the array (execute-in-place, XiP), making it the technology of choice for boot ROMs and firmware storage in embedded systems. Within the memory hierarchy, NOR Flash sits above NAND Flash for random-access reliability and above SRAM/DRAM for non-volatility; it forms the persistent storage tier between battery-backed SRAM and high-density NAND. The MX29F400C series implements the Common Flash Memory Interface (CFI) for device identification, and the bottom-boot layout places small parameter sectors at low addresses - the most common configuration for PC BIOS and bootloader storage where small early-write sectors speed up boot code updates.
Key features include 70 ns maximum access time, sector-erase granularity (16 KB / 8 KB / 32 KB / 64 KB), 100,000 erase cycles per sector endurance, and a JEDEC-standard command set for byte-program and sector/chip erase operations. The device includes hardware sector-protection via the WP#/ACC pin and a hardware reset (RP#) input for safe in-system resets. Embedded algorithms manage program and erase internally, freeing the host controller from timing state machines.
The MX29F400CBTI-70G uses a NOR-cell array with hot-electron injection programming and Fowler-Nordheim tunneling for erase, providing reliable 5V-only operation without the 12V VPP required by older boot-sector Flash. The architecture supports single-cycle word/byte reads, with output enable control for bus sharing and a ready/busy (RY/BY#) output for hardware polling of internal algorithm completion.
Typical applications include PC BIOS ROMs, set-top box boot loaders, networking equipment firmware, industrial control firmware, automotive infotainment boot code, and printer/copier controller firmware. The bottom-boot sector map is preferred when the bootloader resides at the lowest flash addresses and only the small 16K/8K boot sectors need frequent updates.
When designing with this part, observe the recommended decoupling (0.1 uF ceramic at VCC) and route the 48-pin TSOP signals with matched trace lengths for the byte/word data bus. Note that this part is in production but increasingly replaced by SPI NOR devices in new designs - verify the 5V supply and parallel-bus requirement match your system before selection.
This page synthesizes distributor pricing, drop-in alternatives, sector-map details, and practical design notes not found in the manufacturer datasheet alone.
Drop-in alternatives for MX29F400CBTI-70G — 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:
MX29F400CBTC-70G
✅ Drop-In📋 Reference alternative (not in catalog)
MX29F400CBTI-70G-T
✅ Drop-In📋 Reference alternative (not in catalog)
MX29F400CBI-70G
✅ Drop-In📋 Reference alternative (not in catalog)
AM29F400BB-70EC
✅ Drop-In📋 Reference alternative (not in catalog)
AM29F400BB-70EF
✅ Drop-In📋 Reference alternative (not in catalog)
MX29F400CBTI-70G Maximum Ratings & Electrical Characteristics
| Memory Type | Non-volatile FLASH - NOR |
| Memory Size | 4 Mbit |
| Memory Organization | 512K x 8 / 256K x 16 (byte/word mode selectable) |
| Memory Interface | Parallel |
| Access Time | 70 ns (max) |
| Write Cycle Time (Word/Page) | 70 ns |
| Supply Voltage (VCC) | 4.5 V to 5.5 V (single 5V only) |
| Sector Architecture | Bottom Boot (1x 16KB, 2x 8KB, 1x 32KB, 3x 64KB) |
| Program/Erase Endurance | 100,000 cycles per sector (typical) |
| Operating Temperature | -40 C to +85 C (Industrial) |
| Package / Case | 48-TSOP Type I (TFSOP-48, 18.4 mm x 12 mm body, 0.5 mm pitch) |
| Mounting Type | Surface Mount |
| Sector Protection | Hardware via WP#/ACC pin |
| Command Set | JEDEC standard (compatible) with CFI |
| Hardware Reset | RP# input |
| Ready/Busy Output | RY/BY# open-drain |
| RoHS Status | Compliant |
| MSL Level | 3 (168 hours) |
MX29F400CBTI-70G Pin Configuration
| Pin 1 | A11 — Address input 11 |
| Pin 2 | A12 — Address input 12 |
| Pin 3 | A13 — Address input 13 |
| Pin 4 | A14 — Address input 14 |
| Pin 5 | A15 — Address input 15 |
| Pin 6 | A16 — Address input 16 |
| Pin 7 | BYTE# — Byte/word mode select (low = x8, high = x16) |
| Pin 8 | VSS — Ground |
| Pin 9 | DQ15/A-1 — Data bit 15 (word mode) / LSB address (byte mode) |
| Pin 10 | DQ7 — Data bit 7 |
| Pin 11 | DQ14 — Data bit 14 |
| Pin 12 | DQ6 — Data bit 6 |
| Pin 13 | DQ13 — Data bit 13 |
| Pin 14 | DQ5 — Data bit 5 |
| Pin 15 | DQ12 — Data bit 12 |
| Pin 16 | DQ4 — Data bit 4 |
| Pin 17 | VCC — Power supply (5V) |
| Pin 18 | DQ11 — Data bit 11 |
| Pin 19 | DQ3 — Data bit 3 |
| Pin 20 | DQ10 — Data bit 10 |
| Pin 21 | DQ2 — Data bit 2 |
| Pin 22 | DQ9 — Data bit 9 |
| Pin 23 | DQ1 — Data bit 1 |
| Pin 24 | DQ8 — Data bit 8 |
| Pin 25 | DQ0 — Data bit 0 (LSB) |
| Pin 26 | OE# — Output enable (active low) |
| Pin 27 | VSS — Ground |
| Pin 28 | RP# — Hardware reset (active low) |
| Pin 29 | RY/BY# — Ready/Busy output (open drain) |
| Pin 30 | A17 — Address input 17 (MSB) |
| Pin 31 | WE# — Write enable (active low) |
| Pin 32 | WP#/ACC — Write protect / Acceleration pin |
| Pin 33 | A8 — Address input 8 |
| Pin 34 | A9 — Address input 9 |
| Pin 35 | A10 — Address input 10 |
| Pin 36 | A7 — Address input 7 |
| Pin 37 | VCC — Power supply (5V) |
| Pin 38 | A6 — Address input 6 |
| Pin 39 | A5 — Address input 5 |
| Pin 40 | A4 — Address input 4 |
| Pin 41 | A3 — Address input 3 |
| Pin 42 | A2 — Address input 2 |
| Pin 43 | A1 — Address input 1 |
| Pin 44 | A0 — Address input 0 (LSB) |
| Pin 45 | CE# — Chip enable (active low) |
| Pin 46 | VSS — Ground |
| Pin 47 | DQ15/A-1 (alt) — Reserved / duplicate - see pin 9 |
| Pin 48 | NC — Not connected (per datasheet TSOP layout) |
Typical Applications
MX29F400CBTI-70G is suitable for 6 applications: PC BIOS / Motherboard Boot ROM, Set-Top Box / Embedded Bootloader, Industrial PLC / Factory Automation Firmware, Networking Router / Switch Firmware, Automotive Infotainment Boot Code, Printer / Copier Controller Firmware.
PC BIOS / Motherboard Boot ROM
The MX29F400CBTI-70G fits PC BIOS storage because its 4-Mbit density matches legacy BIOS image sizes (typically 1-2 Mbit after compression) and its Bottom Boot sector map places small 8K/16K sectors at the lowest addresses where the boot block resides. The 70 ns access time is compatible with LPC/SPI-bridged BIOS controllers operating at 33 MHz, and the 5V single supply aligns with motherboard standby rails. Placed on the LPC or ISA-style bus, it can be read in execute-in-place (XiP) mode for fast POST code execution. The 100,000-cycle endurance easily handles hundreds of BIOS revisions across the motherboard lifecycle, and the WP#/ACC hardware pin enables BIOS write protection during normal operation - unlocked only by a service jumper.
Recommended
Set-Top Box / Embedded Bootloader
Set-top boxes and embedded Linux devices use the MX29F400CBTI-70G as a parallel NOR boot ROM because the 4 Mbit size accommodates u-boot plus a small kernel image, and the Bottom Boot sectors allow the bootloader itself to be updated independently from the application firmware. The parallel x16 data bus provides the throughput needed for fast boot (often under 2 seconds from reset), which is critical for consumer expectations. The 5V supply rail matches many STB power architectures and avoids needing an LDO. With hardware sector protection via WP#/ACC, the bootloader can be locked once shipped, preventing accidental corruption. The RY/BY# pin allows the host CPU to poll erase/program completion without interrupt-driven software state machines.
Recommended
Industrial PLC / Factory Automation Firmware
Industrial PLCs use the MX29F400CBTI-70G to store firmware and configuration because the -40 C to +85 C industrial temperature grade handles factory floor extremes, and the parallel NOR interface ensures deterministic read latency for time-critical control loops. The 5V supply rail aligns with the 24V-to-5V intermediate bus typical in industrial power designs. The bottom-boot sector map enables field upgrades of the boot block while leaving the main application code read-protected via the WP#/ACC pin. The 70 ns access time keeps the MCU's external memory interface running at full speed without wait states, and the 48-pin TSOP package is robust enough for the vibration and thermal-cycling conditions of factory environments.
Recommended
Networking Router / Switch Firmware
Routers and managed switches use the MX29F400CBTI-70G as a parallel NOR boot Flash because the parallel x8/x16 bus supports the high-speed code execution needed during boot of the network operating system. The 4-Mbit size is sufficient for bootloader plus a small Linux kernel image, and the bottom-boot sector map allows secure OTA update of the bootloader itself. The 5V supply matches typical telecom/datacom power architectures. Hardware sector protection via WP#/ACC enables manufacturers to lock down firmware once shipped, meeting tamper-resistance requirements. The RY/BY# pin supports asynchronous erase completion detection, simplifying firmware-update state machines in the network processor's RTOS.
Recommended
Automotive Infotainment Boot Code
Automotive infotainment head units historically used the MX29F400CBTI-70G as a parallel NOR boot Flash because of its wide operating temperature range and parallel-bus compatibility with legacy automotive SoCs. The 4-Mbit capacity holds the bootloader and early-startup graphics, and the bottom-boot sector map enables OTA bootloader updates with the application firmware locked. The 5V supply rail matches traditional automotive 5V power domains before low-voltage SoCs became dominant. Hardware sector protection via WP#/ACC allows OEMs to lock firmware against tampering, and the 100,000-cycle endurance handles frequent firmware revisions during the vehicle's development phase. Note: modern designs increasingly migrate to QSPI NOR for pin-count savings.
Recommended
Printer / Copier Controller Firmware
Printers and copiers use the MX29F400CBTI-70G to store firmware, font tables, and macros because the parallel NOR interface delivers fast code execution at power-on and the bottom-boot sector map allows separate updates of the boot block. The 4-Mbit capacity holds PostScript interpreters or printer-language firmware plus the boot code. The 5V single-supply operation matches the printer's main power rail without additional LDOs, and the 70 ns access time keeps the printer-controller MCU's external bus running without wait states. Hardware sector protection via WP#/ACC prevents end-user firmware tampering, while the RY/BY# pin supports host polling of erase/program completion during service-mode firmware updates.
Recommended
Recommended Products Summary
Engineering reference data for MX29F400CBTI-70G — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MX29F400CBTC-70G | MX29F400CBTI-70G-T | MX29F400CBI-70G | AM29F400BB-70EC | AM29F400BB-70EF |
|---|---|---|---|---|---|---|
| Package | 48-TSOP Type I | 48-TSOP Type I - same | 48-TSOP Type I - same | 48-TSOP Type I - same | 48-TSOP Type I - same | 48-TSOP Type I - same |
| Brand | Macronix | Macronix | Macronix | Macronix | Spansion | Spansion |
| Memory Density | 4 Mbit | 4 Mbit | 4 Mbit | 4 Mbit | 4 Mbit | 4 Mbit |
| Access Time | 70 ns | 70 ns | 70 ns | 70 ns | 70 ns | 70 ns |
| Supply Voltage | 4.5V - 5.5V | 4.5V - 5.5V | 4.5V - 5.5V | 4.5V - 5.5V | 4.5V - 5.5V | 4.5V - 5.5V |
| Sector Architecture | Bottom Boot | Bottom Boot | Bottom Boot | Top Boot | Bottom Boot | Bottom Boot |
| Operating Temperature | -40 C to +85 C (Industrial) | 0 C to +70 C (Commercial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) | -40 C to +85 C (Industrial) |
| Endurance (per sector) | 100,000 cycles | 100,000 cycles | 100,000 cycles | 100,000 cycles | 100,000 cycles (typ) | 100,000 cycles (typ) |
Key Differentiators
- Bottom Boot sector map optimizes bootloader update granularity (vs MX29F400CBI-70G (Top Boot))
- Cross-brand drop-in compatibility with Spansion AM29F400BB series (vs AM29F400BB-70EC)
- Industrial temperature range for harsh-environment deployments (vs MX29F400CBTC-70G (Commercial temp))
Design Notes
The MX29F400CBTI-70G operates from a single 4.5V-5.5V rail (no 12V VPP needed). Place a 0.1 uF decoupling capacitor as close as possible to each VCC pin (pins 17 and 37) with a low-impedance ground return to the nearest VSS pin. During program and erase operations, the device draws peak currents up to approximately 30 mA; ensure the 5V regulator has adequate transient response to avoid VCC droop below 4.5V during these operations, which can cause algorithm failure.
Route the 48-pin TSOP signals with matched trace lengths within the same bus group (address, data, control). The DQ15/A-1 pin is multiplexed - in byte mode (BYTE# low), pin 9 becomes address bit A-1, the LSB for x8 reads. Keep CE#, OE#, and WE# traces short and free of stubs to avoid ringing on parallel-bus reads. Use a 4-layer PCB with a continuous ground plane beneath the TSOP for signal-integrity and EMI performance, especially for systems with bus clocks above 10 MHz.
Do not issue program or erase commands while the device is in read mode without first writing the unlock cycle - the JEDEC command set requires specific write sequences to enter program/erase modes. Always check the RY/BY# pin (or poll DQ7) for algorithm completion before initiating the next operation. The WP#/ACC pin must be properly managed: leaving it floating or pulled high without intent can cause accidental sector-lockout. The BYTE# pin state is sampled only at reset - changing it dynamically has no effect on the operating mode.
Estimated: continuous read operation at full bus activity (70 ns cycle time across all 16 data lines) draws approximately 30 mA active current at 5V, dissipating roughly 0.15 W. Junction temperature rise is negligible with theta-JA around 60 C/W for the 48-TSOP package - no heatsink is required. However, during program/erase operations, peak currents can double; verify regulator thermal performance during worst-case field firmware updates.
Compliance Information
RoHS compliant per Macronix product page. The 'G' suffix in -70G denotes green/lead-free packaging per Macronix part-number convention. AEC-Q100 is not applicable for this memory IC as Macronix does not market it under the automotive-Q100 program; for automotive applications, verify with Macronix or use a separately qualified part.
