74LS191 Datasheet (Fairchild Semiconductor) - Synchronous 4-Bit Up/Down Counter

74LS191, Synchronous 4-Bit Up/Down Counter

The DM74LS191 circuit is a synchronous, reversible, up/ down counter.

Synchronous operation is provided by having all flip-flops clocked simultaneously, so that the outputs change simultaneously when so instructed by the steering logic.

This mode of operation eliminates the output counting spikes no

74LS191 Features

* s Counts binary s Single down/up count control line s Count enable control input s Ripple clock output for cascading s Asynchronously presettable with load control s Parallel outputs s Cascadable for n-bit applications s Average propagation delay 20 ns s Typical clock frequency 25 MHz s Typical powe