DM74LS169AN
数据手册.pdf同步4位加/减二进制计数器 Synchronous 4-Bit Up/Down Binary Counter
General Description
This synchronous presettable counter features an internal carry look-ahead for cascading in high-speed counting applications. Synchronous operation is provided by having all flip-flops clocked simultaneously, so that the outputs all change at the same time when so instructed by the count-enable inputs and internal gating. This mode of operation helps eliminate the output counting spikes that are normally associated with asynchronous ripple clock counters. A buffered clock input triggers the four master-slave flip-flops on the rising edge of the clock waveform.
Features
Fully synchronous operation for counting and programming.
Internal look-ahead for fast counting.
Carry output for n-bit cascading.
Fully independent clock circuit