This part is a kind of semiconductor called 74LS.

Function of this product has Decade and Binary Counters.

Manufacturers : National Semiconductor

Image and pinout :

Some of the text within the PDF file :

DM74LS90 DM74LS93 Decade and Binary Counters June 1989 DM74LS90 DM74LS93 Decade and Binary Counters General Description Each of these monolithic counters contains four masterslave flip-flops and additional gating to provide a divide-bytwo counter and a three-stage binary counter for which the count cycle length is divide-by-five for the ’LS90 and divideby-eight for the ’LS93 All of these counters have a gated zero reset and the LS90 also has gated set-to-nine inputs for use in BCD nine’s complement applications To use their maximum count length (decade or four bit binary) the B input is connected to the QA output The input count pulses are applied to input A and the outputs are as described in the appropriate truth table A symmetrical divide-by-ten count can be obtained from the �� [ ... ]

74LS PDF Datasheet Download