The UT54ACS169 and the UT54ACTS169 are synchronous 4bit binary counters that feature an internal carry look-ahead for cascading in high-speed counting applications. 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 inputs and internal gating. Synchronous operation helps eliminate the output counting spikes that are normally associated with asynchronous (ripple clock) counters. The clock input triggers the four flip-flops on the rising (positive-going) edge of the clock. The counters are fully programmable (i.e., the outputs may each be preset high or low). The load input circuitry allows loading with the carry-enable output of cascaded counters. Loading is synchronous; applying a low level at the load input disables the counter and causes the outputs to agree with the data inputs after the next clock pulse.