Overview
The STMicroelectronics M27C256B-70C6 is a 256 Kbit EPROM (Erasable Programmable Read-Only Memory) available in both UV (ultra violet erase) and OTP (one time programmable) versions. This device is organized as 32,768 by 8 bits, making it ideally suited for microprocessor systems. The M27C256B is offered in various packages, including FDIP28W (window ceramic frit-seal package), PDIP28, and PLCC32, with the FDIP28W package featuring a transparent lid for UV erasure. The device is also available in ECOPACK® packages, which are lead-free and compliant with environmental standards.
Key Specifications
| Parameter | Description | Value |
|---|---|---|
| Memory Capacity | 256 Kbit (32Kb × 8) | |
| Supply Voltage (Read) | 5V ± 10% | |
| Access Time | 45ns (minimum) | |
| Active Current | 30mA at 5MHz | |
| Standby Current | 100µA | |
| Programming Voltage | 12.75V ± 0.25V | |
| Programming Time | 100µs/Word | |
| Electronic Signature | Manufacturer Code: 20h, Device Code: 8Dh | |
| Packages | FDIP28W, PDIP28, PLCC32 |
Key Features
- Low Power Consumption: Active current of 30mA at 5MHz and standby current of 100µA.
- Two-Line Output Control: Features chip enable (E) and output enable (G) for efficient memory array management.
- Electronic Signature: Allows identification of the device through manufacturer and device codes.
- ECOPACK® Packages: Lead-free packages compliant with environmental standards.
- Programming and Erasure: Supports UV erasure and OTP versions with a programming time of 100µs per word.
Applications
The M27C256B is ideally suited for microprocessor systems and other applications requiring non-volatile memory. It is commonly used in:
- Embedded systems
- Industrial control systems
- Automotive electronics
- Consumer electronics
Q & A
- What is the memory capacity of the M27C256B?
The M27C256B has a memory capacity of 256 Kbit, organized as 32,768 by 8 bits.
- What are the different package options available for the M27C256B?
The device is available in FDIP28W, PDIP28, and PLCC32 packages.
- What is the access time of the M27C256B?
The access time is 45ns (minimum).
- How does the two-line output control function work?
The two-line output control uses chip enable (E) and output enable (G) to manage memory arrays efficiently, ensuring low power dissipation and preventing output bus contention.
- What is the programming voltage and time for the M27C256B?
The programming voltage is 12.75V ± 0.25V, and the programming time is 100µs per word.
- How does the electronic signature mode work?
The electronic signature mode allows the device to be identified through manufacturer and device codes by applying specific voltages to the address lines.
- What are the standby and active current values for the M27C256B?
The standby current is 100µA, and the active current is 30mA at 5MHz.
- Is the M27C256B available in lead-free packages?
- How is the device placed in standby mode?
The device is placed in standby mode by applying a CMOS high signal to the E input.
- What is the purpose of the transparent lid in the FDIP28W package?
The transparent lid in the FDIP28W package allows the user to expose the chip to ultraviolet light for erasure.
