SLYY221 November   2023 ADS124S08 , AFE2256 , REF35 , REF70 , TPS62912 , TPS62913 , TPSM82912 , TPSM82913 , UCC5880-Q1 , UCC5881-Q1

 

  1.   1
  2.   Overview
  3.   At a glance
  4.   Why high voltage?
  5.   Optimizing wide-bandgap FET performance with component innovations
  6.   Selecting the right gate drivers
  7.   Selecting the right controllers
  8.   Maximizing power density with topology innovations
  9.   Achieving extreme efficiency targets with system-level innovation
  10.   Addressing EMI challenges
  11.   Conclusion
  12.   Additional resources

Optimizing wide-bandgap FET performance with component innovations

Wide-bandgap FETs such as silicon carbide (SiC) MOSFETs or gallium nitride (GaN) FETs offer a higher-efficiency alternative to silicon MOSFETs. Wide band-gap FETs have very low or even not reverse recovered charge (Qrr), as well as lower on-resistance under the same voltage levels as silicon MOSFETs, shown in Figure 1.

GUID-20231004-SS0I-4PXL-QW5R-XZ924ZHTQ5QC-low.jpg Figure 1 Theoretical on-resistance vs. blocking voltage.

In addition, almost all other parasitics including gate charge (Qg) and output capacitance (Coss) are much lower in wide band-gap FETs than silicon MOSFETs, leading to much faster switching speeds: an over 150-V/ns slew rate compared to a superjunction silicon MOSFET’s less than 80-V/ns slew rate. With faster switching speeds, the time it takes for power switches to turn on or off is shorter, and switching losses are reduced.