Efficiency calculator

youshang

在efficiency calculator report 中切換工作的MOSFET (Q1&Q2) , 其power loss是一個數值

請問MOSFET power loss 可以breakdown為下列項目嗎?

• Conduction loss
  
• Switching loss
  
• Output capacitance loss
  
• Gate charge loss
  
• Dead time loss
  
• Reverse recovery loss
  

提供原廠工程師回覆建議如下列說明，請您協助參考，謝謝您；



Here is the best explanation of how to measure switching losses and how you can break the losses down into reasonable components.

Application B - Modeling and Measuring Power Stage Efficiency

However, you have to be careful in your  definitions of capacitive losses.  Strictly speaking pure energy storage devices, like capacitors do not have any losses.  The losses are incurred during the charging and the discharging of these devices.   So, if you put a power probe on  an ideal capacitor, you will not measure any losses.  All the losses show up in the charge and discharge circuits.

So, the losses associated with Gate capacitance, for example, show up as losses in the Driver circuit.   

We also are careful to point out that a good driver model is just as important as a good FET model.

Application B is the best written explanation that we have about how to measure this.

We also have a really good Webinars on

MOSFET Switching Losses - A Deep Dive - Part I

MOSFET Switching Losses - A Deep Dive - Part II

and Reverse Recovery

Modeling Reverse Recovery Loss

SIMPLIS is the best tool for  estimating switching losses in switching power supplies.  It is a challenging subject and you need to be very clear in your thinking to get the best results.