The 74HC123 IC is designed as dual retriggerable monostable multivibrators, offering versatile output pulse width control through three methods:

1. Basic Pulse Programming: The output pulse width is determined by selecting an external resistor (REXT) and capacitor (CEXT).
2. Pulse Extension: The basic output pulse width can be extended by retriggering the gated active LOW-going edge input (nA) or the active HIGH-going edge input (nB). By repeating this process, the output pulse period (nQ = HIGH, nQ = LOW) can be prolonged indefinitely. An output delay can be terminated at any time by a LOW-going edge on input nRD, which also inhibits further triggering.
3. Triggering via Reset Input: An internal connection from nRD to the input gates allows the circuit to be triggered by a HIGH-going signal at input nRD, as shown in the function table.

The Schmitt-trigger action on the nA and nB inputs makes the circuit highly tolerant to slower input rise and fall times. 

Features:

• DC triggered from active HIGH or active LOW inputs
• Retriggerable for very long pulses up to 100% duty factor
• Direct reset terminates output pulse
• Schmitt-trigger action on all inputs except for the reset input
• ESD protection: HBM JESD22-A114E exceeds 2000 V, MM JESD22-A115-A exceeds 200 V
• Specified operating temperature ranges: -40°C to +85°C and -40°C to +125°C

Specifications:

• Supply Voltage: -0.5 to +7 V
• Input Clamping Current: +20 mA
• Output Clamping Current: +20 mA
• Output Current: +25 mA
• Supply Current: 50 mA
• Ground Current: -50 mA
• Storage Temperature: -65°C to +150°C

Package Includes:

1 x 74HC123 Dual Retriggerable Monostable Multivibrator IC (74123 IC)

Note: Product images are for illustrative purposes only and may differ from the actual product.