M29W400B 4 Mbit (512Kb x8 or 256Kb x16) Flash Memory

Overview

The M29W400B is a high-performance 4 Mbit non-volatile flash memory device organized as either 512Kb x8 or 256Kb x16. Manufactured using advanced CMOS technology, this component offers fast access times, low power consumption, and high reliability for embedded systems requiring firmware storage. The device features a uniform block architecture with top or bottom boot block configuration, making it suitable for both code and data storage applications.

This flash memory operates on a single 3.0V to 3.6V power supply and incorporates sophisticated write/erase algorithms internally, significantly reducing design complexity for system engineers. With its industry-standard pinout and command set, the M29W400B provides an ideal upgrade path for legacy systems while meeting modern performance requirements.

Key Features

• 4 Mbit (512Kb x8 or 256Kb x16) memory organization
• Single voltage operation: 3.0V to 3.6V
• Fast access time: 70ns maximum
• Low power consumption:
  • Active current: 20mA typical (5MHz)
  • Standby current: 1μA typical
• Flexible sector architecture:
  • Seven 4Kb sectors
  • One 8Kb sector
  • Fifteen 32Kb sectors
  • One 16Kb sector (top or bottom configuration)
• 100,000 write/erase cycles minimum per sector
• 20-year data retention
• Hardware data protection
• Compatible with JEDEC standards
• Industrial temperature range: -40°C to +85°C

Applications

The M29W400B is designed for a wide range of embedded applications requiring reliable non-volatile storage:

• Consumer electronics firmware storage
• Automotive engine control units
• Industrial control systems
• Telecommunications equipment
• Set-top boxes and digital TV
• Network routers and switches
• Medical devices
• Gaming consoles
• BIOS storage for PC motherboards

Electrical Characteristics

Absolute Maximum Ratings

• Voltage on any pin relative to ground: -0.6V to +4.6V
• Operating temperature: -40°C to +85°C
• Storage temperature: -65°C to +150°C
• Power dissipation: 500mW

DC Characteristics (Vcc = 3.0V to 3.6V, T_A = -40°C to +85°C)

• Input low voltage: -0.5V to 0.8V
• Input high voltage: 2.0V to Vcc + 0.5V
• Output low voltage (I_OL = 100μA): 0.2V max
• Output high voltage (I_OH = -100μA): Vcc - 0.2V min
• Standby current (Vcc = 3.6V): 1μA max
• Active read current (5MHz): 20mA typical
• Program/erase current: 30mA typical

AC Characteristics

• Address access time: 70ns max
• Chip enable access time: 70ns max
• Output enable access time: 30ns max
• Byte write pulse width: 50ns min
• Sector erase time: 1s typical
• Chip erase time: 32s typical
• Byte program time: 20μs typical

Functional Description

Memory Organization

The M29W400B offers flexible memory organization options. In x8 mode, the device appears as 512Kb x8 with a single byte-wide data bus. In x16 mode, it operates as 256Kb x16 with a word-wide data bus. The memory array is divided into sectors of different sizes to accommodate various application requirements:

• 8 x 4Kb sectors for boot code storage
• 1 x 8Kb sector for parameter storage
• 15 x 32Kb sectors for main code/data storage
• 1 x 16Kb sector (configurable as top or bottom boot block)

Command Interface

The device uses a standard command set compatible with JEDEC specifications. Key operations include:

• Read/Reset: Returns device to read mode
• Autoselect: Reads manufacturer and device codes
• Program: Writes data to specified address
• Sector Erase: Erases specified sector
• Chip Erase: Erases entire memory array
• Suspend/Resume: Allows interrupt of erase operations

Package Information

The M29W400B is available in several industry-standard packages:

TSOP48 (12x20mm)

• 48-pin Thin Small Outline Package
• 0.5mm pin pitch
• RoHS compliant
• Moisture sensitivity level: 3

PLCC32 (14x14mm)

• 32-pin Plastic Leaded Chip Carrier
• 1.27mm lead pitch
• JEDEC MO-047 standard
• Suitable for socket mounting

BGA48 (6x8mm)

• 48-ball Fine-Pitch Ball Grid Array
• 0.8mm ball pitch
• Ultra-compact footprint
• Ideal for space-constrained applications

Quality and Reliability

The M29W400B meets stringent quality requirements:

• Industrial temperature range operation
• 100,000 minimum program/erase cycles per sector
• 20-year data retention at 85°C
• ESD protection: 2000V minimum (HBM)
• Latch-up immunity: 100mA
• Full production flow burn-in available

Ordering Information

The device is available with several options:

• Speed grade: 70ns, 90ns, 120ns
• Temperature range: Industrial (-40°C to +85°C)
• Package type: TSOP48, PLCC32, BGA48
• Boot block configuration: Top or Bottom

Example ordering code: M29W400BT70N6 (4Mbit, Top Boot Block, 70ns, TSOP48)