7.13.4 Divide-by-N Counters

Chapter 7.13.4 Divide-by-N Counters

Physics Lecture Notes – Phys 395 Electronics Book
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Physics Lecture Notes – Phys 395 Electronics Book

  • CHAPTER 7. DIGITAL CIRCUITS155ENABLEOUTCOUNTCOUNT ENABLEJCKSRQQJCKSRQQJCKSRQQFigure 7.30: A 3-bit synchronous counter.7.13.4Divide-by-N CountersA common feature of many digital circuits is a high-frequency clock with a square waveoutput. If this signal of frequency f drives the clock input of a JKFF wired to toggle oneach trigger, the output of the flip-flop will be a square wave of frequency f/2. This singleflip-flop is a divide-by-2 counter. In a similar manner an n flip-flop binary counter will yieldan output frequency that is f divided by 2n.