Counter Single 8-Bit Sync Binary UP/Down 24-Pin SOIC Tube

These synchronous, presettable, 8-bit up/down counters feature internal-carry look-ahead circuitry for cascading in high-speed counting applications. Synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincidentally with each other when so instructed by the count-enable (ENP\,ENT\) inputs and internal gating. This mode of operation eliminates the output counting spikes normally associated with asynchronous (ripple-clock) counters. A buffered clock (CLK) input triggers the eight flip-flops on the rising (positive-going) edge of the clock waveform.These counters are fully programmable; they may be preset to any number between 0 and 255. The load-input circuitry allows parallel loading of the cascaded counters. Because loading is synchronous, selecting the load mode disables the counter and causes the outputs to agree with the data inputs after the next clock pulse.

Fully Programmable With Synchronous Counting and Loading

SN74ALS867A and ´AS867 Have Asynchronous Clear;SN74ALS869 and ´AS869 Have Synchronous Clear

Fully Independent Clock Circuit Simplifies Use

Ripple-Carry Output for n-Bit Cascading

Package Options Include Plastic Small-Outline (DW) Packages,Ceramic Chip Carriers (FK), and Standard Plastic (NT) and Ceramic(JT) 300-mil DIPs