74LS90 are high-speed 4-bit ripple type counters partitioned into two sections. Each counter has a di - vide-by-two section and either a divide-by-five (LS90), divide-by-six (LS92) or divide-by-eight
(LS93) section which are triggered by a HIGH-to-LOW transition on the clock inputs. Each section can be used eparately or tied together(Q to CP) to form BCD, bi-quinary, modulo-12, or modulo-16 counters. All of the counters have a 2-input gated
Master Reset (Clear), and the LS90 also
has a 2-input gated Master Set (Preset 9).
•Low Power Consumption . . . Typically 45 mW
•High Count Rates . . . Typically 42 MHz
•Choice of Counting Modes . . . BCD, Bi-Quinary, Divide-by-Twelve, Binary
•Input Clamp Diodes Limit High Speed Termination Effects