Texas Instruments SN74LS169B

these synchronous presettable counters feature an internal carry look-ahead for cascading in high speed counting applications. the ls169b and s169 are 4-bit binary counters. synchronous operation is provided by having all flip-flops clocked simultaneously so that the outputs change coincident with each other when so instructed by the count-enable inputs and internal gating. this mode of operation helps eliminate the output counting spikes that are normally associated with asynchronous (ripple-clock) counters. a buffered clock input triggers the four master-slave flip-flops on the rising (positive-going) edge of the clock waveform. these counters are fully programmable; that is the outputs may each be preset to either level. view all in datasheet