Datasheet Summary
54/7490A 54LS/74LS90
DECADE COUNTER
CONNECTION DIAGRAM PINOUT A
DESCRIPTION
- The ’90 is a 4-stage ripple counter containing a high speed flip-flop acting as a divide-by-two and three flip-flops connected as a divideby-five counter. It can be connected to operate with a conventional BCD out put pattern or it can be connected to provide a 50% duty cycle output. In the BCD mode, HIGH signals on the Master Set (MS) inputs set the outputs to BCD nine. HIGH signals on the Master Reset (MR) inputs force all outputs LOW. For a similar counter with corner power pins, see the ’LS290; for dual versions, see the ’LS390 and ’LS490.
ORDERING CODE: See Section 9
PKGS
PIN OUT
MERCIAL...
