Part Number: 74HC123
Function : Dual retriggerable monostable multivibrator with reset
Package: SOP 16 Pin
The 74HC/HCT123 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A.
The 74HC/HCT123 are dual retriggerable monostable multivibrators with output pulse width control by three methods. The basic pulse time is programmed by selection of an external resistor (REXT) and capacitor (CEXT). The external resistor and capacitor are normally connected as shown in Fig.6.
Once triggered, the basic output pulse width may 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 made as long as desired. Alternatively an output delay can be terminated at any time by a LOW-going edge on input nRD, which also inhibits the triggering.
• 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
• Output capability: standard (except for nREXT/CEXT)
• ICCcategory: MSI
Pinout and Function Table
Other data sheets are available within the file: 74HC123D, 74HC123DB, 74HC123N, 74HC123PW