Introduction :
74HC90 (Decade, Divided by twelve AND binary counter- 4-BIT Binary Counter) Each of these monolithic counters contains four master-slave flip-flops and additional gating to provide a divide-by-two counter and a three-stage binary counter for which thecount cycle length is divide-by-five for the 74HS90.
All of these counters have a gated zero reset and the 74HS90 also has gated set-to-nine inputs for use inBCD nine’s complement applications.To use their maximum count length (decade or four bitbinary), the B input is connected to the QA output.
Theinput count pulses are applied to input A and the outputsare as described in the appropriate truth table.
A symmetri-cal divide-by-ten count can be obtained from the 74HS90 counters by connecting the QD output to the Ainput and applying the input count to the B input whichgives a divide-by-ten square wave at output QA.
Features :
- Logic Type:Binary Counter.
- Supply Voltage Min: 4.75V.
- Supply Voltage Max: 5.25V.
- Clock Frequency: 42MHz.
- Logic Case Style: DIP.
- No. of Pins: 14.