The S-75V series is a single gate fabricated by utilizing advanced silicon-gate CMOS technology which provides the inherent benefit of CMOS low power consumption to achieve ultra high speed operation correspond to LSTTL IC' s.
Input voltage is allowed to be applied even if power voltage is not supplied because no diode is inserted between an input pin and VCC.
This allows for interfaces between power supplies of different voltage, output level conversion from 5 V to 3 V and battery backup applications.