Duty Cycle

Definition: Duty cycle is the fraction of time a signal or system is in an active state. It is expressed as a percentage or a ratio of the active time to the total period of the signal.

Key Points:

  • Represents the proportion of time a signal is in a high (or ON) state
  • Can be calculated as: Duty Cycle = (Pulse Width / Period) × 100%
  • A 50% duty cycle means the signal is HIGH for half the period and LOW for the other half
  • Duty cycle is a key characteristic of pulse-width modulation (PWM) signals

Importance:

  • Affects the average power delivered by a signal
  • Impacts the frequency spectrum of a signal
  • Plays a crucial role in power electronics, motor control, and communication systems
  • Variations in duty cycle can affect signal integrity and system performance

Adjusting Duty Cycle:

  • Pulse-width modulation (PWM) techniques
  • Duty cycle correction circuits
  • Feedback control systems

Applications:

  • DC-DC converters
  • Motor speed control
  • Dimming of LEDs
  • Switching power amplifiers
  • Digital communication protocols

Example: For a signal with a period of 10μs and a pulse width of 4μs, the duty cycle is: Duty Cycle = (4μs / 10μs) × 100% = 40%

Understanding and controlling duty cycle is essential for optimizing power efficiency, signal integrity, and system performance in various VLSI applications.