CD74ACT163M

The CD74ACT163M is a synchronous presettable Binary Counter with synchronous reset. It features an internal carry look-ahead for application in high-speed counting designs. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change, coincident with each other, when instructed by the count-enable (ENP, ENT) inputs and internal gating. This mode of operation eliminates the output counting spikes normally associated with synchronous (ripple-clock) counters. A buffered clock input triggers the four flip-flops on the rising (positive-going) edge of the clock waveform. The counters are fully programmable, that is, they can be preset to any number between 0 and 9 or 15. Presetting is synchronous, therefore, setting up a low level at the load input disables the counter and causes the outputs to agree with the setup data after the next clock pulse, regardless of the levels of the enable inputs.