Threshold Voltage

Definition: Threshold voltage (Vth) is the minimum gate-to-source voltage needed to create a conducting path between the source and drain in a MOSFET.

Key Points:

  • Determines the ON/OFF state of a transistor
  • Affects switching speed and power consumption
  • Varies with process technology and transistor design
  • Sensitive to temperature and manufacturing variations

Impact:

  • Lower Vth: faster switching, higher leakage current
  • Higher Vth: slower switching, lower leakage current

Design Considerations:

  • Multi-Vth design for power-performance trade-offs
  • Vth tuning through body biasing
  • Critical for subthreshold circuit design

Importance:

  • Key parameter in transistor modeling and circuit design
  • Crucial for balancing performance and power consumption

Threshold voltage management is fundamental in modern VLSI design, especially for low-power applications.