The CD74HC123M is an integrated circuit (IC) manual-reset monostable multi-vibrator dual retrig monostable manufactured by Texas Instruments. This IC is composed of two identical, independently-operating monostable multi-vibrator circuits that have an active-low trigger input and an active-low output. When triggered, these circuits produce a negative-going, low-amplitude pulse from its output, having a width determined by an external capacitor connected from the discharge pin to the trigger pin. The length of the output pulse is determined by the values of the capacitor and the external resistors connected to the timing terminals. Additionally, this IC has a Retrig pin that when activated can cause the timer to recycle, effectively resetting and retriggering itself. It can operate over a supply voltage ranging from 2V to 6V and has an operating temperature range of -55°C to 125°C.