SN74AS161D

同步4位十年和二进制计数器 SYNCHRONOUS 4-BIT DECADE AND BINARY COUNTERS

description

These synchronous, presettable, 4-bit decade and binary counters feature an internal carry look-ahead circuitry for application in high-speed counting designs. The SN54ALS162B is a 4-bit decade counter. The ’ALS161B, ’ALS163B, ’AS161, and ’AS163 devices are 4-bit binary counters. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincidentally with each other when instructed by the count-enable ENP, ENT inputs and internal gating. This mode of operation eliminates the output counting spikes normally associated with asynchronous ripple-clock counters. A buffered clock CLK input triggers the four flip-flops on the rising positive-going edge of the clock input waveform.

• Internal Look-Ahead Circuitry for Fast Counting

• Carry Output for n-Bit Cascading

• Synchronous Counting

• Synchronously Programmable

• Package Options Include Plastic

   Small-Outline D and Shrink Small-Outline

   DB Packages, Ceramic Chip Carriers FK,

   Standard Plastic N and Ceramic J DIPs