Subthreshold Leakage
Definition: Subthreshold leakage is the current that flows between the source and drain of a MOSFET when the gate voltage is below the threshold voltage.
Key Points:
- Major component of static power consumption
- Increases exponentially as threshold voltage decreases
- Significant in deep submicron technologies
- Highly temperature dependent
Factors Affecting Subthreshold Leakage:
- Threshold voltage
- Channel length
- Temperature
- Drain-source voltage
Reduction Techniques:
- Increasing threshold voltage
- Power gating
- Body biasing
- Stack forcing
Importance:
- Critical in low power design
- Major contributor to standby power consumption
- Limits the scaling of supply voltage in advanced nodes
Managing subthreshold leakage is crucial for power efficiency in modern VLSI designs.