Dynamic power

Dynamic power consists mostly of the switching power.

• The supply voltage VDD and frequency f are known by the designer.
• To estimate dynamic power, one can consider each node of the circuit.
• The capacitance of the node is the sum of the gate, diffusion, and wire capacitances on the node.
• The activity factor can be estimated using switching probability or measured from logic simulations.
• The effective capacitance of the node is, its true capacitance multiplied by the activity factor.
• The switching power depends on the sum of the effective capacitance of all the nodes.v