The UPD74HC123AC is a high-speed silicon gate CMOS monostable multivibrator manufactured by NEC. It provides two independent timing circuits, each capable of producing accurate time delays or pulse widths. These circuits are triggered by either the positive or negative transition of an input signal and are retriggerable, allowing for extended pulse durations.

Applications

• Timing Circuits: Generation of precise time delays for various applications.
• Pulse Width Generation: Creating pulses of specific durations for control signals.
• Delay Lines: Introducing controlled delays in digital signals.
• Frequency Division: Dividing an input frequency by a specific factor.
• Pulse Shaping: Modifying the shape of pulses to meet specific requirements.
• Retriggerable Timers: Applications requiring the extension of pulse duration upon receiving subsequent trigger signals.

Features

• High-Speed Operation: Fast propagation delay times, enabling use in high-frequency applications.
• Dual Monostable Multivibrators: Provides two independent timing circuits in a single package.
• Triggerable from Positive or Negative Edge: Versatile triggering options for different input signals.
• Retriggerable: Allows pulse duration to be extended by retriggering the circuit.
• Wide Operating Voltage Range: Operates over a wide range of supply voltages.
• Low Power Consumption: CMOS technology ensures low power dissipation.
• High Noise Immunity: Provides stable operation in noisy environments.

Benefits

• Accurate Timing: Precise time delays and pulse widths, ensuring reliable operation.
• Versatile Triggering: Flexible triggering options to accommodate different input signal polarities.
• Extended Pulse Duration: Retriggerable capability allows for extending pulse widths as needed.
• High-Speed Performance: Suitable for high-frequency applications requiring fast response times.
• Low Power Consumption: Minimizes power dissipation, making it suitable for battery-powered applications.
• Stable Operation: High noise immunity ensures reliable performance in noisy environments.
• Simplified Circuit Design: Reduces the need for external components, simplifying circuit design.

Technical Specifications

• Operating Voltage Range: 2V to 6V.
• Operating Temperature Range: -40°C to +85°C.
• Trigger Input Voltage (Low): 0V to 0.8V.
• Trigger Input Voltage (High): 2V to VCC.
• Output Voltage (Low): 0V to 0.1V.
• Output Voltage (High): VCC - 0.1V to VCC.
• Quiescent Current: Typically less than 5µA.
• Propagation Delay Time: Typically 15ns to 30ns, depending on the load capacitance and supply voltage.
• Package Type: DIP-16 or SOIC-16.

The UPD74HC123AC is a reliable and versatile monostable multivibrator suitable for a wide range of timing and pulse generation applications. Its high-speed performance, low power consumption, and retriggerable capability make it a valuable component in digital circuit design.