Dynamic Power

Definition: Dynamic power is the power consumed in CMOS circuits due to switching activity.

Key Points:

  • Main component of power consumption in actively switching circuits
  • Occurs during charging and discharging of load capacitances
  • Proportional to switching frequency, capacitance, and square of supply voltage

Formula: P = α * C * V^2 * f

  • α: switching activity factor
  • C: load capacitance
  • V: supply voltage
  • f: clock frequency

Reduction Techniques:

  • Clock gating
  • Voltage scaling
  • Frequency scaling
  • Capacitance reduction

Significance:

  • Dominant in high-performance, actively switching circuits
  • Major focus in power optimization for mobile and battery-operated devices

Dynamic power management is crucial for energy-efficient VLSI design.