74HCT390D,652

The 74HCT390D is a dual Decade Ripple Counter pin compatible with low power Schottky TTL (LSTTL). This dual 4-bit decade ripple counter 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 input (nMR). If the two master reset inputs (1MR and 2MR) are used to simultaneously clear all 8-bit of the counter, a number of counting configurations are possible within one package. Each section is triggered by the high-to-low transition of the clock inputs (nCP0\ and nCP1\). For BCD decade operation, the nQ0 output is connected to the nCP1\ input of, the divide-by-5 section. For bi-quinary decade operation, the nQ3 output is connected to the nCP0\ input and nQ0 becomes the decade output.