I'm trying to calculate the switching loss of the MOSFET which is used for a DC-DC Boost converter. Input Voltage : 9V-16V

Output Voltage : 30V

Output Current : 0.3A.

Switching Freq : 455kHz

Based on this [App Note][1] the Switching loss formula is given on page 3, equation 4.

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If I calculate the switching loss based on the above formula, it comes to around 14W.

In this Article, the formula for calculating the switching loss is different.

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Which one is the correct formula and could you explain the reason for 2 different formulas?

[1]: https://www.ti.com/lit/an/slyt664/slyt664.pdf?ts=1617773788537&ref_url=https%253A%252F%252Fwww.google.com%252F#:~:text=MOSFET%20switching%20losses%20are%20a,as%20shown%20by%20Equation%204.&text=where%20VIN%20%3D%20VDS%20(drain%2D,IG%20is%20the%20gate%20current

  • 1
    \$\begingroup\$ these formulas may well be identical because each of GS2 and GD capacitances is charged by a current \$I_G/2\$ \$\endgroup\$ – V.V.T Apr 7 at 12:15
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    \$\begingroup\$ Switching frequency 455 kHz ... that'll make you popular! \$\endgroup\$ – user_1818839 Apr 7 at 12:27
  • \$\begingroup\$ I'm unable to understand. And why 455kHz would make me popular/ \$\endgroup\$ – Newbie Apr 7 at 13:04
  • \$\begingroup\$ That’s the IF channel for AM radios , some interference is possible nearby. \$\endgroup\$ – Tony Stewart EE75 Apr 7 at 13:49
  • \$\begingroup\$ Also Q=CV and Ig =Vgs/Rg peak during tR,tF so peak power is something like Vg^2/Rg * C * 2f (?) for C=Ciss which is related to Cgd,Cgs or Qgd,Qgs \$\endgroup\$ – Tony Stewart EE75 Apr 7 at 13:55

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