PDF《Application Report》

t forget that the drain to source voltages are equal C and the higher temperature will increase its RDS(on) value. The increasing resistance will cause the current to decrease, therefore the temperature to drop. Eventually, an equilibrium is reached where the parallel connected devices carry similar current levels. Initial tolerance in RDS(on) values and different junction to ambient thermal resistances can cause significant C up to 30% C error in current distribution. MOSFET Technology www.ti.com

4 SLUA618ACMarch 2017CRevised October

2018 Submit Documentation Feedback Copyright ? 2017C2018, Texas Instruments Incorporated Fundamentals of MOSFET and IGBT Gate Driver Circuits 2.1 Device Types Almost all manufacturers have their unique twist on how to manufacture the best power MOSFETs, but all of these devices on the market can be categorized into three basic device types. These are illustrated in Figure 1. Figure 1. Power MOSFET Device Types Double-diffused MOS transistors were introduced in the 1970'

s for power applications and evolved continuously during the years. Using polycrystalline silicon gate structures and self-aligning processes, higher density integration and rapid reduction in capacitances became possible. The next significant advancement was offered by the V-groove or trench technology to further increase cell density in power MOSFET devices. The better performance and denser integration do not come free;

however, as trench MOS devices are more difficult to manufacture. The lateral power MOSFETs have significantly lower capacitances, therefore, they can switch much faster and they require much less gate drive power. www.ti.com MOSFET Technology

5 SLUA618ACMarch 2017CRevised October

2018 Submit Documentation Feedback Copyright ? 2017C2018, Texas Instruments Incorporated Fundamentals of MOSFET and IGBT Gate Driver Circuits 2.2 MOSFET Models There are numerous models available to illustrate how the MOSFET works, nevertheless finding the right representation might be difficult. Most of the MOSFET manufacturers provide Spice and/or Saber models for their devices, but these models say very little about the application traps designers have to face i........