AT27C256R-90PA

Product Overview

Category

AT27C256R-90PA belongs to the category of programmable read-only memory (PROM) chips.

Use

This product 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 stored data remains intact even when power is removed.
• High storage capacity: The AT27C256R-90PA has a storage capacity of 256 kilobits (32 kilobytes).
• Fast access time: With an access time of 90 nanoseconds, it provides quick retrieval of stored data.
• Low power consumption: The chip operates at low power levels, making it suitable for battery-powered devices.

Package

The AT27C256R-90PA is available in a standard 28-pin DIP (Dual Inline Package) format. This package offers ease of integration into various circuit boards and systems.

Essence

The essence of the AT27C256R-90PA lies in its ability to store data reliably and securely, ensuring that the information remains unchanged over time.

Packaging/Quantity

The AT27C256R-90PA is typically packaged in tubes or trays, with each tube or tray containing multiple units of the chip. The exact quantity may vary depending on the supplier and customer requirements.

Specifications

• Storage Capacity: 256 kilobits (32 kilobytes)
• Access Time: 90 nanoseconds
• Operating Voltage: 5 volts
• Operating Temperature Range: -40°C to +85°C
• Data Retention: More than 20 years

Detailed Pin Configuration

The AT27C256R-90PA features a total of 28 pins, each serving a specific purpose. The pin configuration is as follows:

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. A15 - Address Input
17. /OE - Output Enable
18. /CE - Chip Enable
19. /WE - Write Enable
20. VCC - Power Supply (5V)
21. D0 - Data Input/Output
22. D1 - Data Input/Output
23. D2 - Data Input/Output
24. D3 - Data Input/Output
25. D4 - Data Input/Output
26. D5 - Data Input/Output
27. D6 - Data Input/Output
28. D7 - Data Input/Output

Functional Features

The AT27C256R-90PA offers the following functional features:

• Read Operation: The chip allows for the retrieval of stored data through the address inputs and data outputs.
• Write Protection: The chip includes write protection mechanisms to prevent accidental modification of stored data.
• High-Speed Access: With a fast access time of 90 nanoseconds, the chip enables quick retrieval of data.

Advantages and Disadvantages

Advantages

• Non-volatile storage ensures data integrity even in the absence of power.
• High storage capacity allows for the storage of a significant amount of data.
• Fast access time enables quick retrieval of stored information.
• Low power consumption makes it suitable for battery-powered devices.

Disadvantages

• The data stored in the AT27C256R-90PA cannot be modified or updated once programmed.
• Limited storage capacity compared to other memory technologies such as flash memory.

Working Principles

The AT27C256R-90PA operates based on the principle of electrical charge trapping. During programming, the desired data is written into the memory cells by applying appropriate voltage levels to the address and control inputs. Once programmed, the stored data remains intact until a new programming operation is performed.

Detailed Application Field Plans

The AT27C256R-90PA finds applications in various fields, including:

1. Computer Systems: Used for storing firmware, BIOS, and other critical system data.
2. Microcontrollers: Employed to store program code and configuration data.
3. Consumer Electronics: Utilized for storing data such as audio samples, graphics, and device settings.

Detailed and Complete Alternative Models

There are several alternative models available in the market that offer similar functionality to the AT27C256R-90PA. Some notable alternatives include: