74HC123 Datasheet – Monostable Multivibrator – Philips

Part Number: 74HC123

Function : Dual retriggerable monostable multivibrator with reset

Package: SOP 16 Pin

Manufacturer: Philips




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

74HC123 Datasheet

74HC123 Datasheet



Other data sheets are available within the file: 74HC123D, 74HC123DB, 74HC123N, 74HC123PW

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CD4047 Datasheet PDF – Monostable Multivibrator – Fairchild

Part Number: CD4047, CD4047BC, CD4047BCN, CD4047BCM

Function : Low Power Monostable/Astable Multivibrator

Package : SOIC, PDIP 14 Pin Type

Manufacturer: Fairchild Semiconductor

CD4047 image fairchild

The CD4047 is capable of operating in either the monostable or astable mode. It requires an external capacitor (between pins 1 and 3) and an external resistor (between pins 2 and 3) to determine the output pulse width in the monostable mode, and the output frequency in the astable mode.

CD4047 datasheet pdf fairchild


1. Positive- or negative-edge trigger
2. Output pulse width independent of trigger pulse duration
3. Retriggerable option for pulse width expansion
4. Long pulse widths possible using small RC components by means of external counter provision
5. Fast recovery time essentially independent of pulse width
6. Pulse-width accuracy maintained at duty cycles approaching 100%

CD4047 block diagram fairchild

CD4047 Datasheet PDF

CD4047 pdf