DC characteristic #3: Input current (IIN)
Since the CMOS logic IC is a voltage-driven IC, almost no input current (IIN) is required.
DC characteristics of the 74VHC04FT
Example: Input voltage (VIN) vs input current (IIN) curve of the 74VHC04
The input current (IIN) is leakage only and as low as several nanoamperes (nA).