SN74LS290N中文資料安森美半導(dǎo)體數(shù)據(jù)手冊(cè)PDF規(guī)格書(shū)

DECADE COUNTER; 4-BIT BINARY COUNTER

The SN54 /74LS290 and SN54 /74LS293 are high-speed 4-bit ripple type counters partitioned into two sections. Each counter has a divide-by-two section and either a divide-by-five (LS290) or divide-by-eight (LS293) section which are triggered by a HIGH-to-LOW transition on the clock inputs. Each section can be used separately or tied together (Q to CP)to form BCD, Bi-quinary, or Modulo-16 counters. Both of the counters have a 2-input gated Master Reset (Clear), and the LS290 also has a 2-input gated Master Set (Preset 9).

? Corner Power Pin Versions of the LS90 and LS93

? Low Power Consumption . . . Typically 45 mW

? High Count Rates . . . Typically 42 MHz

? Choice of Counting Modes . . . BCD, Bi-Quinary, Binary

? Input Clamp Diodes Limit High Speed Termination Effects