Click to expand full text
MC74HC390
Dual 4−Stage Binary
Ripple Counter with ÷ 2 and ÷ 5 Sections
High−Performance Silicon−Gate CMOS
The MC54/74HC390 is identical in pinout to the LS390. The device inputs are compatible with standard CMOS outputs; with pullup resistors, they are compatible with LSTTL outputs.
This device consists of two independent 4−bit counters, each composed of a divide−by−two and a divide−by−five section. The divide−by−two and divide−by−five counters have separate clock inputs, and can be cascaded to implement various combinations of ÷ 2 and/or ÷ 5 up to a ÷ 100 counter.
Flip−flops internal to the counters are triggered by high−to−low transitions of the clock input. A separate, asynchronous reset is provided for each 4−bit counter.
MC74HC390 Datasheet
