CD74HC390E

The CD74HC390E is a high speed CMOS dual decade Ripple Counter pin compatible with low-power Schottky TTL (LSTTL). It is divided into four separately clocked sections. The counter has two divide-by-2 sections and two divide-by-5 sections. These sections are normally used in a BCD decade or bi quinary configuration, since they share a common master reset (nMR). If the two master reset inputs (1MR and 2MR) are used to simultaneously clear all 8 bits of the counter, a number of counting configurations are possible within one package. The separate clock inputs (nCP0\ and nCP1\) of each section allow ripple counter or frequency division applications of divide-by-2, 4. 5, 10, 20, 25, 50 or 100. Each section is triggered by the high-to-low transition of the input pulses (nCP0\ and nCP1\). For BCD decade operation, the nQ0 output is connected to the nCP1\ input of the divide-by-5 section.