74LS390 Datasheet - Fairchild Semiconductor

74LS390 Dual 4-Bit Decade Counter

Each of these monolithic circuits contains eight masterslave flip-flops and additional gating to implement two individual four-bit counters in a single package. The DM74LS390 incorporates dual divide-by-two and divideby-five counters, which can be used to implement cycle lengths equal to any whole a.

74LS390 Features

* s Dual version of the popular DM74LS90 s DM74LS390individual clocks for A and B flip-flops provide dual ÷ 2 and ÷ 5 counters s Direct clear for each 4-bit counter s Dual 4-bit version can significantly improve system densities by reducing counter package count by 50% s Typical maximum count frequenc

74LS390_FairchildSemiconductor.pdf