4位同步二进制计数器 4-BIT SYNCHRONOUS BINARY COUNTERS
description
These synchronous, presettable counters feature an internal carry look-ahead for application in high-speed counting designs. The ’HC161 devices are 4-bit binary counters. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so instructed by the count-enable ENP, ENT inputs and internal gating. This mode of operation eliminates the output counting spikes that are normally associated with synchronous ripple-clock counters. A buffered clock CLK input triggers the four flip-flops on the rising positive-going edge of the clock waveform.
Wide Operating Voltage Range of 2 V to 6 V
Outputs Can Drive Up To 10 LSTTL Loads
Low Power Consumption, 80-µA Max ICC
Typical tpd = 14 ns
±4-mA Output Drive at 5 V
Low Input Current of 1 µA Max
Internal Look-Ahead for Fast Counting
Carry Output for n-Bit Cascading
Synchronous Counting
Synchronously Programmable