View Full Version : Changing the gate turn on and off resistor to reduce the switching losses

Apr 21st, 2017, 06:43 AM
By how much I can change the gate turn on and off resistor to reduce the switching losses in my MOSFET and increase the efficiency of the PFC converter?

Apr 27th, 2017, 10:29 AM
Not only by changing the gate resistors is the efficiency affected, but also the drain to source peak voltage during turn off as well as the EMI behavior of the converter. This is a very iterative procedure. The gate resistor can be change as much as the efficiency is good enough, the drain-to-source voltage spike during turn off do not exceeds 80% of the MOSFET breakdown voltage during normal operation (according to IPC-9592) and the EMI performance does not exceed the Class A or B (according to the specified application case)* limits of conducted emissions.

May 9th, 2017, 01:56 PM
Just play with the gate resistor R1 of this simple MOSFET inverted buck (https://design.infineon.com/tinademo/tina.php?path=EXAMPLESROOT%7CINFINEON%7C&file=start.tsc)circuit to explore the overall conduction & switching losses
1) click on "Simulate Transient"
2) change R1 to a higher value and simulate again
3) In the Diagram window select View -> Overlay diagram to merge all results
4) compare the power loss of the MOSFET with Process -> Averages

More interesting online simulation examples you can explore on the Infineon Designer (https://www.infineon.com/cms/en/tools/landing/ifxdesigner.html?redirId=56403)landing page.