SLVA720A July   2015  – October 2020 CD14538B , CD14538B-MIL , CD4047B , CD4047B-MIL , CD4098B , CD4098B-MIL , CD54HC123 , CD54HC221 , CD54HC4538 , CD54HCT123 , CD54HCT4538 , CD74HC123 , CD74HC221 , CD74HC423 , CD74HC4538 , CD74HC4538-Q1 , CD74HCT123 , CD74HCT221 , CD74HCT423 , CD74HCT4538 , SN54121 , SN54123 , SN54221 , SN54AHC123A , SN54AHCT123A , SN54LS123 , SN54LS123-SP , SN54LS221 , SN74121 , SN74221 , SN74AHC123A , SN74AHC123A-EP , SN74AHCT123A , SN74LS122 , SN74LS123 , SN74LS221 , SN74LS423 , SN74LV123A , SN74LV123A-EP , SN74LV123A-Q1 , SN74LV221A , SN74LV221A-Q1 , SN74LVC1G123

 

  1. 1Introduction
  2. 2Terminology
  3. 3Theory of Operation
    1. 3.1 Basic Concept
    2. 3.2 Operation
  4. 4Applications
    1. 4.1 General Design Considerations
      1. 4.1.1 Pulse Length Determination
        1. 4.1.1.1 Temperature Stability
    2. 4.2 SN74LVC1G123 Applications
      1. 4.2.1 Switch Debounce
        1. 4.2.1.1 Requirements
        2. 4.2.1.2 Schematic
        3. 4.2.1.3 Component Selection
      2. 4.2.2 Leading and Trailing Edge Detector
        1. 4.2.2.1 Requirements
        2. 4.2.2.2 Schematic
        3. 4.2.2.3 Component Selection
  5. 5Frequently Asked Questions
    1. 5.1 How do I calculate the output pulse length?
    2. 5.2 How do I configure the SN74LVC1G123's inputs for ______ edge triggering?
    3. 5.3 How stable is the output pulse length over VCC changes?
    4. 5.4 How stable is the output pulse length over temperature changes?
    5. 5.5 Which inputs of the SN74LVC1G123 have Schmitt-triggers?
    6. 5.6 Can I connect the Cext pin to ground?
  6. 6Revision History

5.6 Can I connect the Cext pin to ground?

It is best to follow the datasheet recommendations. If your monostable multivibrator recommends not connecting Cext to ground, then do not connect it to ground.

In some monostable multivibrators the Cext pin is internally tied to ground, but in some it is not. If the datasheet is unclear and the information is required, use an ohmmeter to check the resistance between the two pins. If the resistance reads less than 1 Ω, it is safe to connect both to ground.