Heat sink calculations for TOP269E and irfbc40 mosfet as a stackfet configuration

Posted by: mohan.n2293@gm… on 10/10/2017

Hi Pi,
Im designing a power supply for 3-phase input,spec is
vin_min=180
vin_max=440
vout=65W

Please provide guidelines or application notes or links to find out heat sinks for both TOPSWITCH and MOSFET.
Please respond as early as possible.

Comments

Hi mohan
you can check the calculation from EEVblog:

https://youtu.be/8ruFVmxf0zs

Thanks for the reply,

But when it comes to flyback converter their will a conduction loss and switching loss so how should i differentiate that.

Please guide me with suitable reference document.

Hi Mohan,
In flyback converter, you would just sum up the conduction loss and switching loss for total heat dissipation. Usually temperature depends on the ambient temp, size of the board, etc. I suggest to use thermal simulation to find the optimum heat sink size and shape since this is in Mechanical engineering discipline.

Regards.

can you please guide me how thermal simulation can be done .

Hi Mohan,
First is to measure actual power loss by subtracting output power from input power.
Then one by one, measure every components power loss. then enter this data on your thermal software simulator.

Regards.

Please suggest me any thermal solution related software

FloTherm is a good thermal simulation tool.