CD74HC688NSR

Product Overview

• Category: Integrated Circuit
• Use: Arithmetic Logic Unit (ALU)
• Characteristics: High-speed, CMOS logic, 8-bit magnitude comparator
• Package: SOIC-20
• Essence: The CD74HC688NSR is a high-performance integrated circuit designed for digital arithmetic and logic operations. It is commonly used in applications that require comparison of two 8-bit binary numbers.
• Packaging/Quantity: The CD74HC688NSR is available in a standard SOIC-20 package and is typically sold in reels of 2500 units.

Specifications

• Supply Voltage: 2V to 6V
• Operating Temperature Range: -40°C to +85°C
• Propagation Delay: 9 ns (typical)
• Input Current: ±1µA (maximum)
• Output Current: ±25mA (maximum)

Detailed Pin Configuration

The CD74HC688NSR has a total of 20 pins, which are assigned specific functions as follows:

1. A0: Input pin for the least significant bit (LSB) of the first 8-bit number.
2. A1: Input pin for the second bit of the first 8-bit number.
3. A2: Input pin for the third bit of the first 8-bit number.
4. A3: Input pin for the fourth bit of the first 8-bit number.
5. A4: Input pin for the fifth bit of the first 8-bit number.
6. A5: Input pin for the sixth bit of the first 8-bit number.
7. A6: Input pin for the seventh bit of the first 8-bit number.
8. A7: Input pin for the most significant bit (MSB) of the first 8-bit number.
9. B0: Input pin for the LSB of the second 8-bit number.
10. B1: Input pin for the second bit of the second 8-bit number.
11. B2: Input pin for the third bit of the second 8-bit number.
12. B3: Input pin for the fourth bit of the second 8-bit number.
13. B4: Input pin for the fifth bit of the second 8-bit number.
14. B5: Input pin for the sixth bit of the second 8-bit number.
15. B6: Input pin for the seventh bit of the second 8-bit number.
16. B7: Input pin for the MSB of the second 8-bit number.
17. G: Enable pin for the comparator.
18. LT: Output pin indicating that A < B.
19. EQ: Output pin indicating that A = B.
20. GT: Output pin indicating that A > B.

Functional Features

• High-speed operation allows for efficient comparison of two 8-bit numbers.
• CMOS logic ensures low power consumption and compatibility with a wide range of digital systems.
• The CD74HC688NSR can be cascaded to compare larger binary numbers.
• The enable pin (G) provides control over the comparator's operation, allowing for flexibility in system design.

Advantages and Disadvantages

Advantages: - High-speed operation enables quick comparison of 8-bit numbers. - Low power consumption due to CMOS technology. - Compatibility with various digital systems. - Cascadable for comparing larger binary numbers.

Disadvantages: - Limited to 8-bit comparison, not suitable for larger data sizes. - Requires external control signal (enable pin) for proper operation.

Working Principles

The CD74HC688NSR utilizes a combination of digital logic gates to compare two 8-bit binary numbers. It performs a bit-by-bit comparison, starting from the most significant bit (MSB) down to the least significant bit (LSB). The comparator generates three output signals: LT (A < B), EQ (A = B), and GT (A > B), indicating the relationship between the two input numbers.

Detailed Application Field Plans

The CD74HC688NSR is commonly used in various applications that require the comparison of two 8-bit binary numbers. Some specific application fields include:

1. Microcontrollers: Used for comparing data values in microcontroller-based systems.
2. Digital Signal Processing: Enables efficient comparison of digital signals in DSP algorithms.
3. Data Encryption: Utilized in cryptographic systems for comparing encryption keys.
4. Industrial Automation: Used in control systems for comparing sensor readings or process variables.
5. Communication Systems: Enables comparison of digital data packets in communication protocols.

Detailed and Complete Alternative Models

• SN74HC688N: Similar functionality and pin configuration, but available in a DIP-20 package.
• CD74HCT688E: Compatible with TTL logic