74VHC393

The 74VHC393 is an advanced high speed CMOS 4-bit Binary Counter 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. It contains two independent counter circuits in one package, so that counting or frequency division of 8 binary bits can be achieved with one IC. The 74VHC393 changes state on the negative going transition of the CLOCKpulse. The counter can be reset to "0" (Q₀Q₃ = "L") by a HIGH at the CLEAR input regardless of other inputs.

An input protection circuit of the 74VHC393 ensures that 0V to 7V can be applied to the input pins without regard to the supply voltage voltage.This device can be used to interface 5V to 3V systems and two supply systems such as battery back up. This circuit prevents device destruction due to mismatched supply and input voltages.