Hitachi HD74HC4520
the HD74HC4520 dual binary counter consist of two identical, independent, internally synchronous 4-stage counters. The counter stages are type D flip-flops, with interchangeable Clock and Enable lines for incrementing on either the positive-going or negative-going transition as required when cascading multiple stages. Each counter can be cleared by applying a high level on the Reset line.DESCRIPTION
The HD74HC4518 dual BCD counter and In addition, the HD74HC4518 will count out of all undefined states within two clock periods. These complementary MOS up counters find primary use in multi-stage synchronous or ripple counting applications requiring low power dissipation and/or high noise immunity.FEATURES
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● High Speed Operation High Output Current: Fanout of 10 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C) Function Table Clock Enable H L X X L H X X Reset L L L L L L H Operation Increment counter Increment counter No change No change No change No change Q0 to Q 3 = L HD74HC4518/HD74HC4520 Pin Arrangement Clock A Enable A Q0 A Q1 A Q2 A Q3 A Reset A GND 1 2 3 4 5 6 7 8 (Top view) C Q0 Q1 Q2 Q3 R R Q3 Q2 Q1 Q0 C 16 VCC 15 Reset B 14 Q3 B 13 Q2 B 12 Q1 B 11 Q0 B 10 Enable B 9 Clock B 2 HD74HC4518/HD74HC4520 Timing Diagram 1 Clock Enable Reset 1 Q0 Q1 HD74HC4518 Q2 Q3 Q...