3.3.2 Voltage Scaling

The operating speed of a circuit depends on the supply voltage. It is common practice to optimize the power performance ratio by adjusting the supply voltage. Noise margins, transistor threshold voltage and punch through limit the allowable range of supply voltage. Within the allowable range, Equation 3.1 predicts that when the supply voltage is scaled by a factor of $s_{v}$ the dynamic power consumption scales by $s_{v}^{2}$.