Description

74LS393 – Dual 4-Bit Binary Counters

General Description
Each of these monolithic circuits contains eight master slave flip-flops and additional gating to implement two individual four-bit counters in a single package. The DM74LS393 comprises two independent four-bit binary counters each having a clear and a clock input. N-bit binary counters can be implemented with each package providing the capability of divide-by-256. The DM74LS393 has parallel outputs from each counter stage so that any submultiple of the input count frequency is available for system-timing signals.

Features
■ Dual version of the popular DM74LS93
■ DM74LS393 dual 4-bit binary counter with individual clocks
■ Direct clear for each 4-bit counter
■ Dual 4-bit versions can significantly improve system densities by reducing counter package count by 50%
■ Typical maximum count frequency 35 MHz
■ Buffered outputs reduce possibility of collector commutation