# Heat Sink Simulation Error

**URL:** <https://forum.plexim.com/t/heat-sink-simulation-error/657>\
**Category:** PLECS\
**Tags:** thermal-model, mosfet, heatsink\
**Created:** [May 11, 2019, 6:56pm UTC](https://forum.plexim.com/t/heat-sink-simulation-error/657 "2019-05-11T18:56:24Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![yalbannaii](https://avatars.discourse-cdn.com/v4/letter/y/6a8cbe/32.png) [@yalbannaii](https://forum.plexim.com/u/yalbannaii)\
**Post date:** [May 11, 2019, 6:56pm UTC](https://forum.plexim.com/t/heat-sink-simulation-error/657/1 "2019-05-11T18:56:24Z")

</div>

I am trying to calculate the switching and conduction losses of MOSFETs in my circuit. I used a thermal library model to add the power loss data to the switches. The circuit simulates fine without the heat sink. Once I added it to the circuit I got a bunch of errors.

 ![error1.JPG](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/1X/4fa32519bb83a58cb42229af281f6a71511c2949.jpeg)

 ![error2.JPG](https://europe1.discourse-cdn.com/flex006/uploads/plecs/original/1X/32628726cc0b5f63171dd1fd512819aac33e46a5.jpeg)

---

<div class="post-metadata">

**Author:** ![Kris\_Eberle](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/kris_eberle/32/6_2.png) [@Kris\_Eberle](https://forum.plexim.com/u/Kris_Eberle)\
**Post date:** [May 13, 2019, 6:05pm UTC](https://forum.plexim.com/t/heat-sink-simulation-error/657/2 "2019-05-13T18:05:43Z")

</div>

Hello,

Are you able to attach an example model?

Thank you,

Kris

---

<div class="post-metadata">

**Author:** ![yalbannaii](https://avatars.discourse-cdn.com/v4/letter/y/6a8cbe/32.png) [@yalbannaii](https://forum.plexim.com/u/yalbannaii)\
**Post date:** [May 13, 2019, 6:43pm UTC](https://forum.plexim.com/t/heat-sink-simulation-error/657/3 "2019-05-13T18:43:03Z")

</div>

Attached is the circuit model. You need to add a thermal description to the switches. The thermal description used is C2M0080120D. You can download it and add it to the switches.

[buckfinal.plecs](https://forum.plexim.com/uploads/short-url/6tE2qPdxEhrUl1ztOF6CKqIwI9c.plecs) (22 KB)

---

<div class="post-metadata">

**Author:** ![Kris\_Eberle](https://dub1.discourse-cdn.com/flex006/user_avatar/forum.plexim.com/kris_eberle/32/6_2.png) [@Kris\_Eberle](https://forum.plexim.com/u/Kris_Eberle)\
**Post date:** [May 21, 2019, 1:38pm UTC](https://forum.plexim.com/t/heat-sink-simulation-error/657/4 "2019-05-21T13:38:52Z")

</div>

Hello, you just need to provide a gate resistance value, e.g. 2.5 ohms.