SN54LS690

The SN54LS690 is a type of synchronous counters with output registers and multiplexed 3-state outputs. SN54LS690 incopor ates synchronous counters, four-bit D-type registers, and quadruple two line to one line multiplexers with three-state outputs in a single 20-pin package.

Features of SN54LS690 are: (1)4 bit counters/registers; (2)multiplexed outputs for counter or latched data; (3)3-sta te outputs drive bus lines directly; (4)decade counter, direct clear.

The absolute maximum ratings and recommeded operating conditions of the SN54LS690 can be summarized as: (1)supply voltage: 7V; (2)input voltage: 7V;(3)operating free air temperature range:-55 to 125; (4)storage tempera ture rang:-65 to 150; (5)off-state output voltage: 5.5V. Recommended operating conditions: (1)supply voltage: 4.5V min, 5V typ and 5.5V max; (2)high-level input voltage: 2V min; (3)low-level input voltage: 0.7V max; (4)high-level output current:-1 max; (5)low-level output current: 12mA max; (6)clock frequency: 0MHz min and 20MHz max; (7)pulse duration: 25ns min, etc.