4位二进制计数器，同步清除 4-Bit Binary Counter with Synchronous Clear
General Description
The VHC163 is an advanced high-speed CMOS device 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 VHC163 is a high-speed synchronous modulo-16 binary counter. This device is synchronously presettable for application in programmable dividers and has two types of Count Enable inputs plus a Terminal Count output for versatility in forming multistage counters. The CLK input is active on the rising edge. Both PE and MR inputs are active on low logic level. Presetting is synchronous to rising edge of CLK and the Clear function of the VHC163 is synchronous to CLK. Two enable inputs ENP and ENT and Carry Output are provided to enable easy cascading of counters, which facilitates easy implementation of n-bit counters without using external gates.
Features
■ High speed: fMAX = 185 MHz typ at VCC = 5V
■ Low power dissipation: ICC = 4 µA max at TA = 25°C
■ Synchronous counting and loading
■ High-speed synchronous expansion
■ High noise immunity: VNIH = VNIL = 28% VCC min
■ Power down protection is provided on all inputs.
■ Low noise: VOLP = 0.8V max
■ Pin and function compatible with 74HC163