Input-Tolerant and Output Power-Down Protection Functions Available with Each Series

The following table shows whether each CMOS logic IC series provides the input-tolerant and output power-down protection functions.

By family input-tolerant and output power-down protection functions
Series Part Number

Operating voltage range (V)

Input-tolerant function

Output power-down protection

Standard CMOS TC4000B
3 to 18 -*1 -
High-Speed TC74HC 2 to 6 -*1 -
TC74HCT 4.5 to 5.5
Advanced TC74AC 2 to 5.5 - -
TC74ACT 4.5 to 5.5
Very-High-Speed 74VHC
2 to 5.5 -
74VHCT 4.5 to 5.5
74VHCV 1.8 to 5.5
Low-Voltage 74LCX 1.65 to 3.6
Very-Low-Voltage TC74VCX 1.2 to 3.6

*1: TC4049BF/BP, TC4050BF/BP, TC74HC4049BP/BF/BFT, 74HC4049D, TC74HC4050BP/BF/BFT and 74HC4050D have the input-tolerant function that allows level shifting from a higher voltage to a lower voltage.


Handling of Unused Input Pins
Input Rise and Fall Time Specifications
Multiple Outputs from a General-Purpose CMOS Logic IC Come Into Conflict (Short-Circuiting)
Connecting a Load Capacitance to a CMOS Output Pin
Calculating the Operating Supply Current and Power Dissipation
Level Shifting Using an Input-Tolerant Function
Example of Application of the Power-Down Protection Function (Partial Power-Down)
Types of Noise to be Noted
Countermeasures for Reducing Switching Noise
Countermeasures for Signal Reflection
Countermeasures for Crosstalk
Countermeasures for Hazards
Countermeasures for Metastability
Countermeasures for Latch-Up
Countermeasures for ESD Protection


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