AT27C256R-12RI

Product Overview

Category

The AT27C256R-12RI belongs to the category of programmable read-only memory (PROM) chips.

Use

This chip is primarily used for storing data that needs to be permanently stored and cannot be modified. It is commonly used in various electronic devices such as computers, microcontrollers, and consumer electronics.

Characteristics

• Non-volatile: The data stored in the AT27C256R-12RI remains intact even when the power is turned off.
• High storage capacity: This chip has a storage capacity of 256 kilobits, allowing it to store a large amount of data.
• Fast access time: With an access time of 120 nanoseconds, the AT27C256R-12RI provides quick retrieval of stored data.
• Low power consumption: This chip operates on low power, making it suitable for battery-powered devices.
• Durable: The AT27C256R-12RI is designed to withstand harsh environmental conditions and has a long lifespan.

Package and Quantity

The AT27C256R-12RI is available in a 28-pin dual in-line package (DIP). It is typically sold in reels or tubes containing multiple units.

Specifications

• Manufacturer: Atmel Corporation
• Part Number: AT27C256R-12RI
• Memory Type: Programmable Read-Only Memory (PROM)
• Storage Capacity: 256 kilobits (32 kilobytes)
• Access Time: 120 nanoseconds
• Supply Voltage: 5V
• Operating Temperature Range: -40°C to +85°C
• Package Type: 28-pin DIP

Pin Configuration

The AT27C256R-12RI has a total of 28 pins, each serving a specific function. Here is the detailed pin configuration:

1. A0 - Address Input
2. A1 - Address Input
3. A2 - Address Input
4. A3 - Address Input
5. A4 - Address Input
6. A5 - Address Input
7. A6 - Address Input
8. A7 - Address Input
9. A8 - Address Input
10. A9 - Address Input
11. A10 - Address Input
12. A11 - Address Input
13. A12 - Address Input
14. A13 - Address Input
15. A14 - Address Input
16. /OE - Output Enable
17. /CE - Chip Enable
18. /WE - Write Enable
19. I/O0 - Data Input/Output
20. I/O1 - Data Input/Output
21. I/O2 - Data Input/Output
22. I/O3 - Data Input/Output
23. I/O4 - Data Input/Output
24. I/O5 - Data Input/Output
25. I/O6 - Data Input/Output
26. I/O7 - Data Input/Output
27. Vcc - Power Supply (5V)
28. GND - Ground

Functional Features

The AT27C256R-12RI offers the following functional features:

• Read Operation: The chip allows for the retrieval of stored data by providing the appropriate address inputs and enabling the output.
• Write Protection: The chip has a write enable pin (/WE) that can be used to protect the stored data from accidental modification.
• High-Speed Access: With an access time of 120 nanoseconds, the AT27C256R-12RI provides fast access to stored data.
• Low Power Consumption: This chip operates on low power, making it energy-efficient and suitable for battery-powered devices.

Advantages and Disadvantages

Advantages

• Non-volatile memory ensures data retention even without power.
• High storage capacity allows for the storage of a large amount of data.
• Fast access time enables quick retrieval of stored information.
• Durable design ensures reliability in various environmental conditions.

Disadvantages

• Data cannot be modified once programmed, limiting its flexibility compared to other memory types.
• Limited write cycles: The AT27C256R-12RI has a finite number of times it can be written to before it becomes unreliable.

Working Principles

The AT27C256R-12RI is based on the principle of electrically programmable read-only memory (EPROM). It uses a grid of transistors and floating-gate MOSFETs to store data. During programming, electrical charges are trapped in the floating gate, altering the transistor's behavior and storing the desired data. Once programmed, the data remains intact until it is erased using ultraviolet light.

Application Field Plans

The AT27C256R-12RI finds applications in various fields, including:

1. Computer Systems: Used for storing firmware, BIOS, and other critical system data