L2FET is a 5V gate-driven power MOSFET that is compatible with a 5V power supply for use in logic circuitry. L2FETs retain the on resistance, drain current, and blocking voltage ratings of their 10V predecessors, but operate from a much less costly 5V supply. The reduction in gate drive voltage is the result of halving the thickness of the gate insulator from the industry standard 100nm to 50nm (500Å). Since the surface inversion of the MOS channel is determined by the gate insulator voltage field, halving the insulator thickness halves the required gate voltage to achieve the same surface inversion, thereby not compromising drain characteristics.
The document presents a comparison between Logic Level FETs (L2FETs), which operate from a 5V supply, and standard power MOSFETs requiring a 10V gate drive. It highlights that L2FETs offer twice the switching speed and four times lower dynamic dissipation while maintaining similar on-resistance and current ratings.
The text explains these performance differences using a new characterization method that models the power MOSFET as a vertical JFET driven in cascade by a lateral MOS structure. The note includes detailed analysis of switching waveforms under both conventional voltage drive and constant current drive conditions.
The device is designed to operate with a gate drive between zero and five volts.
The measured fall time is 73 nanoseconds.