The TC74VHC123AFK is a high-speed CMOS dual retriggerable monostable multivibrator from Toshiba. As part of the VHC (Very High-Speed CMOS) family, it offers the speed characteristics of bipolar logic along with the low power consumption of CMOS. The device consists of two independent monostable multivibrators. Each multivibrator can be triggered by either a rising or falling edge. The output pulse width is determined by external resistor (Rext) and capacitor (Cext) values. The retriggerable feature extends the output pulse if a trigger arrives before the end of the timing cycle.

Applications

• Timing circuits
• Pulse generation
• Delay circuits
• Missing pulse detection
• Frequency discrimination

Features

• High-speed operation
• Low power dissipation
• Retriggerable monostable operation
• Wide operating voltage range: 2 V to 5.5 V
• Schmitt-trigger inputs
• Pulse width adjustable via external R and C
• Pin compatible with HC123 and LS123

Benefits

• Fast response times enable precise timing functions.
• Low power consumption reduces heat and extends battery life.
• Extends pulse width if triggered before completion of current cycle.
• Versatile due to the wide operating voltage.
• Improved noise immunity due to Schmitt-trigger inputs.
• Adjustable pulse width allows customization.
• Can easily replace older HC and LS logic.

Additional Details

The TC74VHC123AFK is packaged in a small outline package (SOP). The 'AFK' suffix likely indicates specific packaging or temperature range characteristics. Consult the manufacturer's datasheet for exact specifications. The use of external resistors and capacitors gives a great deal of control over pulse width. The retriggerable function is key for watchdog timer applications.