资 源 简 介
CD4059 standard "A" Series types are divide-by-N down-counters that can be programmed to divide an input frequency by any number "N" from 3 to 15,999. The output signal is a pulse one clock-cycle wide occurring at a rate equal to the input frequency divided by N. This single output has TTL drive capability. The down-counter is preset by means of 16 jam inputs.
The three Mode-Select Inputs Ka, Kb, and Kc determine the modulus ("divide-by" number) of the first and last counTIng secTIons in accordance with the truth table shown in Table 1. Every TIme the first (fastest) counTIng section goes through one cycle, it reduces by 1 the number that has been preset (jammed) into the three decades of the intermediate counting section and into the last counting section, which consists of flip-flops that are not needed for operating the first counting section.
