LM5143A-Q1: How to find QOSS and EOSS

DARSHAN M M V

Part Number: LM5143A-Q1
Other Parts Discussed in Thread: LM5143

Tool/software:

Hello team,

I am trying to calculate the total power loss of a MOSFET used for LM5143 which is very important factor , in the data sheet I refer ed to the formulas mentioned in the datasheet, some part of the formulas QOSS and EOSS are unknown , please help me to find the unknown parameters which is marked in the attachment.

If there is any specific formulas to find out QOSS and EOSS please provide me the formulas or the way to calculate them

over 1 year ago

0 Timothy Hegarty over 1 year ago

TI__Guru 74052 points

Hi Darshan,

Qoss is the area under the Coss vs. Vds curve at a given voltage and is sometimes given by the FET vendor in the data sheet. Eoss is not typically provided for Si FETs (more for GaN), so you may want to ask the FET vendor. In any event, you can use the LM5143 quickstart calculator to assist with loss calculations.

https://www.ti.com/tool/LM5143DESIGN-CALC

Regards,

Tim