Encyclopedia Entry: 74HC123D/AUJ

Product Information Overview

• Category: Integrated Circuit (IC)
• Use: Multivibrator and Timer
• Characteristics: High-speed operation, low power consumption, wide operating voltage range
• Package: 16-pin SOIC (Small Outline Integrated Circuit)
• Essence: Dual retriggerable monostable multivibrator
• Packaging/Quantity: Available in reels of 2500 units

Specifications

• Supply Voltage Range: 2V to 6V
• Operating Temperature Range: -40°C to +125°C
• Propagation Delay Time: 22 ns (typical)
• Trigger Pulse Width Range: 23 ns to 1000 ns
• Output Current: ±4 mA
• Input Capacitance: 3.5 pF (typical)

Detailed Pin Configuration

The 74HC123D/AUJ IC has a total of 16 pins, each serving a specific purpose:

1. Pin 1: Clear Input (CLR)
2. Pin 2: Retriggerable Monostable Trigger Input (TRIGA)
3. Pin 3: Retriggerable Monostable Output (OUTA)
4. Pin 4: Ground (GND)
5. Pin 5: Retriggerable Monostable Trigger Input (TRIGB)
6. Pin 6: Retriggerable Monostable Output (OUTB)
7. Pin 7: Positive Supply Voltage (VCC)
8. Pin 8: Control Voltage (CV)
9. Pin 9: Discharge (DIS)
10. Pin 10: Output Enable (OE)
11. Pin 11: Retriggerable Monostable Trigger Input (TRIGA)
12. Pin 12: Retriggerable Monostable Output (OUTA)
13. Pin 13: Ground (GND)
14. Pin 14: Retriggerable Monostable Trigger Input (TRIGB)
15. Pin 15: Retriggerable Monostable Output (OUTB)
16. Pin 16: Positive Supply Voltage (VCC)

Functional Features

The 74HC123D/AUJ is a dual retriggerable monostable multivibrator IC. It offers the following functional features:

• Retriggerable operation allows for extending the output pulse width by applying additional trigger pulses.
• The device can be triggered either by positive or negative edges of the input signals.
• The output pulse width is determined by an external resistor and capacitor connected to the CV pin.
• The IC provides separate inputs and outputs for two independent monostable multivibrators.

Advantages and Disadvantages

Advantages: - High-speed operation enables efficient timing applications. - Low power consumption makes it suitable for battery-powered devices. - Wide operating voltage range allows for compatibility with various systems.

Disadvantages: - Limited output current may restrict its use in certain high-current applications. - The 16-pin SOIC package may require careful handling during assembly.

Working Principles

The 74HC123D/AUJ operates based on the principles of retriggerable monostable multivibrators. When a trigger pulse is applied to the TRIGA or TRIGB input, the corresponding output (OUTA or OUTB) generates a pulse whose width is determined by the external resistor and capacitor connected to the CV pin. Additional trigger pulses applied before the output pulse ends will extend the pulse width.

Detailed Application Field Plans

The 74HC123D/AUJ finds applications in various fields, including:

1. Timing circuits in digital systems
2. Pulse width modulation (PWM) generation
3. Frequency division and counting circuits
4. Delay circuits for synchronization purposes
5. Control signal generation in microcontroller-based systems

Detailed and Complete Alternative Models

Some alternative models that offer similar functionality to the 74HC123D/AUJ IC include:

1. CD74HC123E: Dual retriggerable monostable multivibrator, available in a 16-pin DIP package.
2. SN74HC123N: Dual retriggerable monostable multivibrator, available in a 16-pin PDIP package.
3. MC74HC123AN: Dual retriggerable monostable multivibrator, available in a 16-pin PDIP package.

These alternatives can be considered based on specific requirements and availability.

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