General Description

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

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

n Dual version of the popular DM74LS93

n DM74LS393 dual 4-bit binary counter with individual

clocks

n Direct clear for each 4-bit counter

n Dual 4-bit versions can significantly improve system

densities by reducing counter package count by 50%

n Typical maximum count frequency 35 MHz

n Buffered outputs reduce possibility of collector commutation