Encyclopedia Entry: 74HC123D

Product Overview

Category

The 74HC123D belongs to the category of integrated circuits (ICs), specifically digital logic ICs.

Use

This IC is commonly used in electronic circuits for various applications, including signal timing, pulse generation, and frequency division.

Characteristics

• High-speed operation
• Wide operating voltage range
• Low power consumption
• Compatibility with TTL (Transistor-Transistor Logic) inputs
• Monostable and astable multivibrator functionality

Package

The 74HC123D is available in a dual in-line package (DIP) format.

Essence

The essence of the 74HC123D lies in its ability to generate precise timing signals and control the duration of output pulses.

Packaging/Quantity

Typically, the 74HC123D is packaged in tubes or reels, containing a specific quantity of ICs per package. The exact quantity may vary depending on the manufacturer and supplier.

Specifications

• Supply Voltage Range: 2V to 6V
• Operating Temperature Range: -40°C to +125°C
• Output Current: ±4mA
• Propagation Delay: 15ns (typical)
• Trigger Pulse Width: 25ns (minimum)

Pin Configuration

The 74HC123D has a total of 16 pins, which are assigned specific functions as follows:

1. Clear (CLR)
2. A Input
3. B Input
4. Ground (GND)
5. Control Voltage (CV)
6. Trigger (TR)
7. Reset (RD)
8. Output (Q)
9. Complementary Output (/Q)
10. VCC (Positive Power Supply)
11. Bypass Capacitor (BYP)
12. External Resistor (REXT)
13. External Capacitor (CEXT)
14. Control Voltage (CV)
15. Trigger (TR)
16. Reset (RD)

Functional Features

The 74HC123D offers the following functional features:

• Monostable Multivibrator: Generates a single output pulse of a specific duration when triggered.
• Astable Multivibrator: Produces a continuous train of output pulses with a fixed frequency and duty cycle.
• Clear Function: Resets the circuit to its initial state.
• Control Voltage: Adjusts the timing characteristics of the output pulses.
• Trigger Input: Initiates the pulse generation process.

Advantages and Disadvantages

Advantages

• High-speed operation allows for precise timing control.
• Wide operating voltage range enables compatibility with various electronic systems.
• Low power consumption makes it suitable for battery-powered applications.
• TTL compatibility simplifies integration with existing circuits.

Disadvantages

• Limited output current may restrict certain high-power applications.
• Propagation delay can introduce timing inaccuracies in time-critical systems.

Working Principles

The 74HC123D operates based on the principles of digital logic. It utilizes internal flip-flops and gates to generate and control the timing signals. The monostable multivibrator mode triggers a single output pulse of a defined duration, while the astable multivibrator mode generates a continuous train of pulses.

Detailed Application Field Plans

The 74HC123D finds application in various fields, including: 1. Timing circuits in microcontrollers and microprocessors. 2. Frequency division in communication systems. 3. Pulse width modulation (PWM) in motor control circuits. 4. Signal conditioning in sensor interfaces. 5. Clock synchronization in digital systems.

Alternative Models

Several alternative models are available that offer similar functionality to the 74HC123D. Some notable alternatives include: - CD74HC123E - SN74HC123N - MC74HC123AN

These alternatives may differ in terms of package type, voltage range, and other specifications. It is important to select the appropriate alternative based on specific application requirements.

In conclusion, the 74HC123D is a versatile digital logic IC that provides precise timing control and pulse generation capabilities. Its high-speed operation, wide voltage range, and compatibility with TTL inputs make it suitable for various applications across different industries.