SN54LS669J

The SN54LS669J from Texas Instruments is a high-speed, synchronous, presettable 4-bit binary up/down counter. It features internal carry look-ahead circuitry, enabling cascading for n-bit synchronous applications without additional external gating. This synchronous operation ensures that all flip-flops are clocked simultaneously, minimizing output counting spikes.

The counter has a buffered clock input that triggers on the positive-going edge of the clock waveform. It is fully programmable, allowing outputs to be preset to any level. The load input circuitry supports synchronous loading, where a low level at the load input disables the counter and synchronizes the outputs with the data inputs after the next clock pulse. The direction of the count is controlled by the up/down input.

Designed for military applications, the SN54LS669J operates within a temperature range of -55°C to 125°C. It utilizes the LS technology family and comes in a CDIP (J) package. Key features include buffered outputs, a fully independent clock circuit, and a carry output for cascading.

This counter is suitable for applications requiring precise and synchronous counting, such as digital systems, control circuits, and frequency division where reliable and fast counting is essential.