Doubts about DPA422PN
Hi, I am using PIExpert software do project a small dc-dc converter with an output power of about 6W.
I was able to use the program just fine and chose the DPA422 DIP-8 version.
The thing is the software tells me to use a heatsink with it, but I remember seeing on the datasheet that heatsinks were not necessary on the dip version with this kind of power output.
So my question is: Should I use a heatsink? Would I have to buy the TO package for that?
Thank you,
Leonardo Alvim Muricy
Comments
Ok, so in my case I guess its easier to just use the TI package to connect it to my "heatsink plane"on the system.
Thank you.
leomuricy -
We handle heatsinking almost identically in that adequate heatsinking can typically be provided with a simple PCB copper area connected to the Source pins of our device.
I'm not sure how the TI device you're using implements this. But one of the selling points of our devices is that they are all (with a few exceptions) source referenced. This means that your heatsink (physical or PCB copper areas) is electrically "quiet" and not a high-frequency switching node. This feature can help greatly reduce EMI complications in power supply designs.
Also, by using our devices, you have access to some of our IP regarding conducted and radiated EMI. Specifically, provided you're using a PI part, you can use our E-Shield transformer winding technology which reduces primary to secondary winding capacitance. This helps with conducted and radiated EMI. Sometimes, the reductions in EMI are so large that many designs can forgo the typical primary to secondary Y-cap (reducing part count and design cost).
-The Traveler
Ok, thank you very much.
In an old product, we used to use the top210pfi and as I can see now we also used only the pcb copper area too.
The EMI (specially the conducted one) is very important for us since we are trying to get certification on our new project. Of course the dpa part is a small one (considering the rest of the circuit), but it helps a lot.
If you give me an idea of your application, specs, requirements, etc, I'd be more than happy to help you put together a quick PI Expert design or see if there is an existing reference design you could leverage to shorten your development time.
Our E-Shield technology, depending on the application, can be a great way to minimize conducted EMI. If you want, I can give you some tips/advice on ways to minimize conducted EMI as well as typical problem areas of the power supplies that need attention.
-The Traveler
Our project is pretty much done by now, but thank you.
Do you have a schematic file for the DPA422PN? I know the company does not create spice libs, but I wonder if the schematic ones can be found.
Thank you again
We don't provide spice models of our ICs but a simplified block diagram is provided in figure 2 of the DPA Switch datasheet. The functional block diagram in conjunction with the datasheet parameters would allow you to put together a basic device model yourself with most circuit modeling/simulation software.
-The Traveler
Leonardo -
Thank you for the interest in our products!
All of our products require some kind of heatsinking. For lower-power designs, this heatsinking can often be provided by created a sufficiently large enough copper area connected to the Source pins.
If you're using the PI Expert design software, when you click on the device heatsink (in the menu on the left hand side of the software), you have the option of choosing PCB copper or a physical heatsink. You also get to choose the PCB copper weight (2 ounce, 4 ounce, etc) and it will tell you approximately how much copper area needs to be provided depending on the ambient temperature you entered for the design as well as whether or not you told the software if it was an adapter (no air circulation) or open enclosure design.
-The Traveler