Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Reverse recovery losses of mosfet body diode

Status
Not open for further replies.

Selvam_Perumal

Junior Member level 2
Joined
Mar 7, 2018
Messages
24
Helped
1
Reputation
2
Reaction score
1
Trophy points
3
Activity points
228
Can anyone tell me how to calculate the reverse recovery losses of a mosfet body diode which is used for full wave rectification in the secondary side of an isolated converter
 

Hi,

It depends how much you want to go into details.

But generally: P(t) = V(t) x I(t).
This is true for any waveform and any electronic device.
If you now calculate the average of P(t) over a full signal period then you have the perfect value.

Simpler methods
If you know the average current (not RMS current) through the diode, then you may calculate with a constant voltage drop.
(Use the voltage drop according the current in times of current flow, don't use the average current here)
Example:
10A for 10us every 10ms
--> look into the datasheet for the voltage drop at 10A. Let's say it's 1.1V.
The average current is: 10A × 10us / 10ms = 10mA
P = 1.1V x 10mA = 11mW

If you just want the reverse recovery power, then just use the part of the time/currentvoltage that is responsible for the reverse recovery.

Klaus

- - - Updated - - -

Added:

I just did an internet search.
Did you go through the existing application notes and discussions?

Klaus
 

You really want to not use the body diode, rather than
calculate its losses. Other bad things can happen when
the body diode is lit up and the drain is pulled high again.

Getting realistic recovery time numbers to use, may need
more than reading a datasheet. This is highly variable
with part type and temperature.
 

a mosfet body diode which is used for full wave rectification in the secondary side of an isolated converter
Why? It can be either operated as synchronous rectifier or replaced by a fast diode.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top