M27C400 4 Mbit EPROM

Overview

The M27C400 is a high-performance 4 Mbit (512K x 8) Erasable Programmable Read-Only Memory (EPROM) designed for applications requiring non-volatile storage. This component utilizes advanced CMOS technology to deliver reliable data retention and low power consumption. The M27C400 is housed in a standard 32-pin package, making it compatible with a wide range of systems and development tools.

With its fast access time and robust architecture, the M27C400 is ideal for embedded systems, industrial controls, and legacy computing applications. The device supports standard EPROM programming and erasure procedures, ensuring ease of integration into existing designs.

Features

• High-Density Storage: 4 Mbit capacity organized as 512K x 8 bits.
• Fast Access Time: Typical access times ranging from 70 ns to 150 ns, depending on the variant.
• Low Power Consumption: CMOS technology ensures efficient operation with active current as low as 30 mA.
• Wide Voltage Range: Operates at 5V ± 10%, making it compatible with standard logic levels.
• UV Erasable: Data can be erased via exposure to ultraviolet light, allowing for reprogramming.
• Industrial Temperature Range: Supports operation from -40°C to +85°C for harsh environments.
• Standard Package: Available in a 32-pin DIP (Dual In-line Package) for easy integration.
• Compatibility: Pin-compatible with other EPROMs in the 27C series, facilitating upgrades.

Applications

The M27C400 is widely used in applications requiring reliable, non-volatile memory storage. Key application areas include:

• Embedded Systems: Firmware storage for microcontrollers and industrial controllers.
• Legacy Computing: BIOS and boot ROMs for older computer systems.
• Telecommunications: Code storage in networking equipment and communication devices.
• Automotive Electronics: Engine control units (ECUs) and infotainment systems.
• Medical Devices: Program storage in diagnostic and monitoring equipment.
• Industrial Automation: Configuration data and control algorithms for PLCs.

Electrical Characteristics

Absolute Maximum Ratings

• Supply Voltage (V_CC): -0.5V to +7.0V
• Input Voltage (V_IN): -0.5V to V_CC + 0.5V
• Operating Temperature Range: -40°C to +85°C
• Storage Temperature Range: -65°C to +150°C

DC Characteristics

• Supply Current (Active): 30 mA max at 5V, 1 MHz
• Supply Current (Standby): 100 µA max
• Input Leakage Current: ±1 µA max
• Output Leakage Current: ±1 µA max

AC Characteristics

• Address Access Time (t_ACC): 70 ns, 90 ns, 120 ns, 150 ns (depending on speed grade)
• Chip Enable Access Time (t_CE): 70 ns, 90 ns, 120 ns, 150 ns
• Output Enable Access Time (t_OE): 35 ns max
• Write Pulse Width (t_WP): 50 ns min

Package Information

32-Pin DIP (Dual In-line Package)

• Package Dimensions: 42.67 mm x 10.16 mm (1.68 in x 0.4 in)
• Pin Pitch: 2.54 mm (0.1 in)
• Lead Material: Tin-plated copper
• Mounting Style: Through-hole

Pin Configuration

• Pins A0-A18: Address inputs for memory location selection.
• Pins O0-O7: Data outputs (tri-state during programming).
• CE (Pin 20): Chip Enable (active low).
• OE (Pin 22): Output Enable (active low).
• PGM (Pin 32): Program pulse input (active low during programming).
• V_PP (Pin 1): Programming voltage (12.5V during programming, V_CC during read).
• V_CC (Pin 28): Supply voltage (5V ± 10%).
• GND (Pin 14): Ground reference.

Programming and Erasure

The M27C400 follows standard EPROM programming and erasure procedures:

• Programming: Data is written using a 12.5V programming voltage (V_PP) and a series of timed pulses. Each byte is verified after programming to ensure accuracy.
• Erasure: The entire memory array is erased by exposing the quartz window to ultraviolet light (wavelength 2537 Å) for a minimum of 15 minutes at an intensity of 12,000 µW/cm².

Reliability and Quality

The M27C400 is designed for high reliability, with the following characteristics:

• Endurance: Minimum 100 programming/erasure cycles per byte.
• Data Retention: 10 years minimum at 55°C after programming.
• ESD Protection: All pins are protected against electrostatic discharge up to 2000V.

Conclusion

The M27C400 4 Mbit EPROM is a versatile and reliable memory solution for applications requiring non-volatile storage. Its combination of high density, fast access times, and industrial-grade robustness makes it suitable for a wide range of embedded and legacy systems. With standard packaging and compatibility with existing EPROM programmers, the M27C400 remains a practical choice for developers and engineers.