AT27C256R-90RI

Product Overview

Category

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

Use

This chip is commonly used for storing non-volatile data in electronic devices. It allows users to write data onto the chip during manufacturing and then read it back later.

Characteristics

• Non-volatile: The stored data remains intact even when power is removed.
• High storage capacity: The AT27C256R-90RI can store up to 256 kilobits (32 kilobytes) of data.
• Fast access time: With a speed rating of 90 nanoseconds, it provides quick access to stored information.
• Reliable: The chip has a high endurance and can withstand multiple write and erase cycles without data loss.

Package

The AT27C256R-90RI comes in a standard integrated circuit (IC) package. It is typically housed in a plastic dual in-line package (PDIP), which provides protection and easy integration into electronic circuits.

Essence

The essence of the AT27C256R-90RI lies in its ability to store and retrieve data reliably, making it an essential component in various electronic devices.

Packaging/Quantity

The chip is usually packaged in reels or tubes, with each reel or tube containing a specific quantity of chips. The exact packaging and quantity may vary depending on the manufacturer and customer requirements.

Specifications

• Storage Capacity: 256 kilobits (32 kilobytes)
• Access Time: 90 nanoseconds
• Supply Voltage: 5 volts
• Operating Temperature Range: -40°C to +85°C
• Package Type: Plastic Dual In-Line Package (PDIP)

Pin Configuration

The AT27C256R-90RI chip has a total of 28 pins. 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. A15 - Address Input
17. /OE - Output Enable
18. /CE - Chip Enable
19. /WE - Write Enable
20. VSS - Ground
21. DQ0 - Data Output 0
22. DQ1 - Data Output 1
23. DQ2 - Data Output 2
24. DQ3 - Data Output 3
25. DQ4 - Data Output 4
26. DQ5 - Data Output 5
27. DQ6 - Data Output 6
28. DQ7 - Data Output 7

Functional Features

The AT27C256R-90RI offers the following functional features:

• Read Operation: The chip allows users to read data stored in its memory array by providing the appropriate address inputs and enabling the chip.
• Write Operation: During manufacturing, data can be written onto the chip using specialized programming equipment. Once programmed, the data becomes non-volatile and can only be read.
• Output Enable: The /OE pin enables or disables the data outputs, allowing for efficient control of data flow.
• Chip Enable: The /CE pin activates or deactivates the chip, ensuring that data is accessed only when required.
• Write Enable: The /WE pin enables or disables the write operation, preventing accidental modification of stored data.

Advantages and Disadvantages

Advantages

• Non-volatile storage: The chip retains data even when power is removed.
• High storage capacity: Offers ample space for storing data in electronic devices.
• Fast access time: Provides quick retrieval of information.
• Reliable: Can withstand multiple write and erase cycles without data loss.

Disadvantages

• Limited write capability: Once programmed, the data cannot be modified or erased, making it unsuitable for applications requiring frequent data updates.
• Higher cost compared to other memory technologies: PROM chips tend to be more expensive than alternatives like EEPROM or flash memory.

Working Principles

The AT27C256R-90RI utilizes a technology called floating-gate MOS (metal-oxide-semiconductor) to store data. During programming, electrical charges are trapped in the floating gate, altering the transistor's behavior and storing the desired data. When reading, the presence or absence of charge in the floating gate determines the output state of each memory cell.

Detailed Application Field Plans

The AT27C256R-90