Other Parts Discussed in Thread: LM3478, LM5122, TPS40210
Hi,
In running a simulation of the LM3478, the part gets up to around 125C with an ambient of 30C.
The design should take 2S LiPo input (around 7-8.4V) and output 11.5V @ 6A.
What am I missing here?
Here is the link to the design:
http://webench.ti.com/appinfo/webench/scripts/SD2.cgi?ID=165469::power::luis.cordova@ti.com
Please let me know if the link does not work. Your support is appreciated!
Hi Luis,
I took a look of your WEBENCH design and the thermal simulator did modeled the temperatures correctly and it reached 120+ deg. C. The results show the co-heating effects of all the power elements per the typical EVM we have in the WEBENCH. This EVM in WEBNECH is by no means the most thermally efficient board layout. Actually, it's more cater toward optimized for electrically.
Since this is a simulator, you have the capability to optimize the design by selecting better efficient components, adding more thermal vias and increasing the copper weight to reduce overall max. temperature. As I have shown below, the max. temp is at 95 deg.C.
Another options is to consider using synchronous boost controllers which are typically have better efficiency (LM5122, TPS40210)
Let us know if you have more questions.
