The CD4518 Dual BCD Up-Counter and CD4520 Dual Binary Up-Counter each consist of two identical, internally synchronous 4-stage counters. The counter stages are D-type flip-flops having interchangeable CLOCK and ENABLE lines for incrementing on either the positive-going or negative-going transition.

Features of CD4518 (CMOS Dual Up Counter):

• Medium-speed operation
• 6-MHz typical clock frequency at 10 V
• Positive- or negative-edge triggering
• Synchronous internal carry propagation
• 100% tested for quiescent current at 20 V
• Maximum input current of 1 µA at 18 V over full package-temperature range; 100 nA at 18 V and 25°C

Applications of CD4518 (CMOS Dual Up Counter):

• Multistage synchronous counting.
• Multistage ripple counting.
• Frequency dividers.