The 74HC123PW,118 from NXP is a dual retriggerable monostable multivibrator with reset. It is a monolithic integrated circuit that can be used to generate a single pulse of a predetermined width in response to a trigger signal. The pulse width is determined by the values of two external components, a resistor and a capacitor.

The 74HC123PW,118 has two trigger inputs, nA and nB. When either of these inputs is triggered, the output pulse begins. The output pulse width is determined by the values of the external resistor (REXT) and capacitor (CEXT). The output pulse can be terminated early by applying a LOW signal to the nRD input.

The 74HC123PW,118 is a versatile device that can be used in a variety of applications, including:

• One-shot timers
• Pulse generators
• Frequency dividers
• Schmitt triggers
• Reset circuits
• Pulse shapers
• Delay circuits

The 74HC123PW,118 is available in a variety of packages, including the 16-pin TSSOP package. It is a high-performance device that can operate at speeds up to 20 MHz.

Here is a more detailed description of the operation of the 74HC123PW,118:

• When either of the trigger inputs, nA or nB, is triggered, the output pulse begins.
• The output pulse width is determined by the values of the external resistor (REXT) and capacitor (CEXT). The following equation can be used to calculate the output pulse width:

Output pulse width = 1.1 * REXT * CEXT

• The output pulse can be terminated early by applying a LOW signal to the nRD input.
• The 74HC123PW,118 has a retriggerable feature. This means that the output pulse can be extended by retriggering either of the trigger inputs, nA or nB.
• The 74HC123PW,118 also has a reset feature. This means that the output pulse can be terminated at any time by applying a LOW signal to the nRD input.

Here is an example of how the 74HC123PW,118 can be used to generate a one-shot timer:

1. Connect a resistor and capacitor to the REXT and CEXT pins, respectively. The values of the resistor and capacitor will determine the output pulse width.
2. Connect a trigger signal to one of the trigger inputs, nA or nB.
3. Connect the output of the 74HC123PW,118 to the device that needs to be triggered.

When the trigger signal is applied, the output pulse will begin. The output pulse will last for the amount of time determined by the values of the external resistor and capacitor. Once the output pulse has ended, the 74HC123PW,118 will be ready to be triggered again.

The 74HC123PW,118 is a powerful and versatile device that can be used in a variety of applications. It is a high-performance device that can operate at speeds up to 20 MHz.