The VHC273 is an advanced high speed CMOS Octal D-type flip-flop fabricated with silicon gate CMOS technology. It achieves the high speed operation similar to equivalent Bipolar Schottky TTL while maintaining the CMOS low power dissipation. The register has a common buffered Clock (CP) which is fully edge-triggered. The state of each D input, one setup time before the LOW-to-HIGH clock transition, is transferred to the corresponding flip-flop’s Q output. The Master Reset (MR) input will clear all flip-flops simultaneously. All outputs will be forced LOW independently of Clock or Data inputs by a LOW voltage level on the MR input. An input protection circuit insures that 0V to 7V can be applied to the inputs pins without regard to the supply voltage. This device can be used to interface 5V to 3V systems and two supply systems such as battery backup. This circuit prevents device destruction due to mismatched supply and input voltages.