Switching Power Dissipation

• Occurs when device changes state or switching of charge in and out of CL , capacitance

• Flow of current across the transistor’s impedence

• Pswitching = t * CL * V2dd * f

  • t= average number of transition per cycle
  • f = clock frequency
  • CL= effective capacitance

• Increases with clock frequency

• Decreases quadratically with supply voltage

• 85-90% of active power consumption

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