Encyclopedia Entry: 74LV123D/AUJ

Product Overview

Category

The 74LV123D/AUJ belongs to the category of integrated circuits (ICs).

Use

This IC is commonly used in digital electronics for various applications such as timing, pulse generation, and synchronization.

Characteristics

• Low-voltage operation: The 74LV123D/AUJ operates at low voltage levels, typically between 1.65V and 5.5V.
• Dual retriggerable monostable multivibrator: It consists of two independent retriggerable monostable multivibrators, which can be triggered by either positive or negative edges of an input signal.
• Schmitt-trigger inputs: The IC features Schmitt-trigger inputs that provide hysteresis, allowing for better noise immunity and signal conditioning.
• High-speed operation: With a propagation delay of only a few nanoseconds, the 74LV123D/AUJ ensures fast and efficient signal processing.
• Wide temperature range: This IC can operate reliably over a wide temperature range, typically from -40°C to 125°C.

Package and Quantity

The 74LV123D/AUJ is available in a small-outline integrated circuit (SOIC) package. It is supplied in tape and reel packaging, with a quantity of 250 units per reel.

Specifications

• Supply Voltage Range: 1.65V to 5.5V
• Input Voltage Range: 0V to VCC
• Output Voltage Range: 0V to VCC
• Maximum Operating Frequency: 100 MHz
• Propagation Delay: 6 ns (typical)
• Operating Temperature Range: -40°C to 125°C

Pin Configuration

The 74LV123D/AUJ has a total of 16 pins, which are assigned specific functions as follows:

1. CLR1: Clear input for multivibrator 1
2. A1: Trigger input for multivibrator 1
3. B1: Retrigger input for multivibrator 1
4. GND: Ground (0V reference)
5. C1: Output of multivibrator 1
6. VCC: Positive supply voltage
7. RCext1: External resistor/capacitor connection for multivibrator 1
8. RBext1: External resistor/capacitor connection for multivibrator 1
9. Q1: Complementary output of multivibrator 1
10. Q1: Output of multivibrator 1
11. CLR2: Clear input for multivibrator 2
12. A2: Trigger input for multivibrator 2
13. B2: Retrigger input for multivibrator 2
14. C2: Output of multivibrator 2
15. RCext2: External resistor/capacitor connection for multivibrator 2
16. RBext2: External resistor/capacitor connection for multivibrator 2

Functional Features

The 74LV123D/AUJ offers the following functional features:

• Retriggerable Monostable Multivibrator: Each multivibrator can be triggered by a positive or negative edge of an input signal, and the output pulse width can be extended by retriggering.
• Independent Operation: The two multivibrators operate independently, allowing for separate timing and pulse generation functions.
• Schmitt-trigger Inputs: The Schmitt-trigger inputs provide noise immunity and signal conditioning, ensuring reliable operation even in noisy environments.
• Fast Propagation Delay: With a propagation delay of only 6 ns, the IC enables high-speed signal processing.

Advantages and Disadvantages

Advantages

• Low-voltage operation allows for compatibility with a wide range of digital systems.
• Retriggerable multivibrator design provides flexibility in pulse generation and timing applications.
• Schmitt-trigger inputs enhance noise immunity and signal conditioning.
• Fast propagation delay enables high-speed signal processing.

Disadvantages

• Limited maximum operating frequency compared to some other ICs in the same category.
• Availability may vary depending on the supplier and market demand.

Working Principles

The 74LV123D/AUJ operates based on the principles of retriggerable monostable multivibrators. Each multivibrator consists of flip-flops, gates, and external resistors/capacitors. When triggered by an input signal, the multivibrator generates an output pulse with a duration determined by the external RC time constant. The pulse width can be extended by retriggering the multivibrator before the pulse ends.

Application Field Plans

The 74LV123D/AUJ finds application in various fields where precise timing, pulse generation, or synchronization is required. Some potential application areas include:

1. Digital