SN5490A

The SN5490A is type of decade counter, which has gated set-to-nine inputs for use in BCD nine's complement applic ations. To use the maximum count length of the counter, the CKB input is combined to the QA output. The input cou nt pulse are applied to CKA input and the outputs are in the appropriate function table. A symmetrical divide-by-ten count can be obtained from the SN5490A by connecting the QD output to the CKA input and applying the input count to the CKB input which gives a divede-by-ten square wave at output QA.

The absolute maximum ratings and electrical characteristics of the SN5490A can be summarized as: (1)supply voltag e: 7V; (2)input voltage: 5.5V;(3)operating free-air temperature range: -55 to 125; (4)storage temperature rang: -65 to 150; (5)interemitter volatge: 5.5V. Electrical characteristics: (1)high-level input voltage: 2V min; (2)low-level input voltage: 0.8V max; (3)input clamp voltage(VCC=min, I1=-12mA): -1.5V max; (4)high level input current(VCC=max, V1=2.4V): 40uA max; (5)low level input current(VCC=max, V1=0.4V):-1.6mA max; (6)short-circuit output current(VCC=max):-20mA min and-57mA max; (7)supply current(VCC=max): 29mA typ and 42mA max; (8)high level output voltage(VCC=MIN, VIH=2V, VIL=0.8V, IOH=-800uA): 2.4V min and 3.4V max; (8)low-level output voltage(VCC =MIN, VIH=2V, VIL=0.8V, IOH=16mA): 0.2V typ and 0.4V max, etc.