74LS123 Dual Mono Multivibrator With Clear


The 74LS series of integrated circuits (ICs) was one of the most popular logic families of transistor-transistor logic (TTL) logic chips. 74LS series is a bipolar, low-power Schottky IC. 74LS123 d-c triggered multivibrators feature output pulse-duration control by three methods. The basic pulse time is programmed by the selection of external resistance and capacitance values (see typical application data).

74LS123 Features

  • Two Independent Retriggerable Monostable Multivibrators
  • Retriggerable to 100% Duty Cycle
  • Input Clamp Diodes
  • Operating Temperature up to 70°C
  • Standard TTL Switching Voltages

74LS123 Specifications

Supply Voltage4.75 – 5.25Vdc
Maximum Clock Frequency40Mhz
Power Dissipation2mW/gate @100kHz
Minimum Output Current8mA
Propagation Delay10nS
Fan Out (TTL Loads)20

74LS123 Pinout Diagram

74LS123 Pin Description

Pin NoPin NameDescription
11AData Input Pin 1A
21BData Input Pin 1B
3CLR’Invert Clear Pin
41Q’Active Low Output 1
52QActive High Output 2
62 C(ext)External Capacitor 2
72Rext/C(ext)External Resistor/External Capacitor 2
92AData Input Pin 2A
102BData Input Pin 2B
112CLR’Invert Clear Pin 2
122Q’Active Low Output 2
131QActive High Output 1
141 C(ext)External Capacitor 1
151 R(ext)/C(ext)External Resistor/External Capacitor 1
16VCCPositive Supply

74LS123 Circuit


  • Timers
  • Pulse generators
  • waveform generators
  • Sweep generators for CRTs (cathode ray tubes)

74LS123 Alternative Equivalent


Download 74LS123 Dual Mono Multivibrator With Clear Datasheet from the link given below.