Digital waveform generation Which digital circuit is commonly used to produce several repetitive, evenly sequenced digital waveforms suitable for timing and sequencing applications?

Introduction / Context:
Digital systems often require multiple repetitive timing waveforms with specific phase relationships. Counters and shift registers can generate such patterns for scanning displays, timing state machines, and frequency division. One classic solution is the Johnson (twisted-ring) counter.

Given Data / Assumptions:

• A need for multiple repetitive digital waveforms.
• Looking for a single circuit type (not simple gates) that inherently produces sequences.
• Ideal, noise-free logic behavior for conceptual understanding.

Concept / Approach:
A Johnson shift counter is a feedback shift register where the complement of the last stage is fed to the first. With n flip-flops it produces 2n unique states, each corresponding to a distinct output pattern across the register taps. These taps provide multiple repetitive waveforms with defined duty cycles and phase offsets.

Step-by-Step Solution:

Verification / Alternative check:
Compare with a simple ring counter (no inversion feedback). Johnson counters double the state count for the same number of stages and provide rich waveform sets, often preferred for pattern generation.

Why Other Options Are Wrong:

• Inverter / OR / AND gates: Single logic gates do not generate multi-phase repetitive sequences by themselves; they only implement basic logic operations.

Common Pitfalls:
Confusing a clock oscillator (which outputs a single square wave) with a counter-based sequencer that provides several distinct outputs. Johnson counters require a clock source but provide multiple phased outputs.

Final Answer:
a Johnson shift counter