Finish up with the Line Tool to box it off. Try to center the part as much as possible to make your life easier when adding it and moving it around. Save the symbol (as well as the library if you haven’t already). Now we’ll handle the package. There are several ways to do this, but we’ll do it the most manual way for now, just in case we ever get a new part that’s not in Eagle at all. The part has several different packages, but we’ll use the biggest one in this case, since if we were to actually create the board, it would be the easiest to use. Packages come in many different types and names, often redundantly so as you’ll find out. We’ll be using the DDC package, also known as Plastic Small Outline . While they give many views, we’re most interested in the footprint – this is how much space we should leave on the board for the part to sit in. Dimensions shown below in millimeters (from the datasheet). Name Add Pin Line
Let’s Hit New Package , PAC , and name it “TPS799”or something similar. The following window should open. Once again, very similar to what we have seen before, but with two critical new options. The Add Via Tool allows us to add a hole to the footprint that is used for leads or pins. The Add Pad Tool allows us to add a pad for any surface mount part. Lastly, we’ll need to use the Grid Tool to make sure that the minimum grid spacing lines up with the smallest significant figure we have – here 0.05mm. Add Via Grid Edit Add Pad Ruler
I suggest using a 0.5mm grid, with a 0.05mm alt setting. Add a pad, and place it relatively near the center. Right click on it, Properties , and change Smd Size to “1.1 x 0.6”. This automatically sizes the pad to the correct dimensions – if it’s off by 90 degrees, rotate it. Now use the Ruler to go and measure out the appropriate distance for the next pad. Remember to hold ALT as you do so – otherwise we’ll be on the main grid dimension, not the finer one. I’ve attached a picture of what the output should like below. Once that is done, copy and paste the previous pad and place it along the same line. Now this is clearly going to get pretty painful if we want to do this for every pad. Fortunately for us, we can get around this with a little math. Delete the ruler drawing for now, we won’t need it. Add another new pad via copy paste, just putting it anywhere. Right click, select Properties on the first pad, and note its Position . Now do the same to the newly added pad, but just move it to the appropriate point – either 0.95mm up, or 2.7mm out. Absolute position doesn’t mean anything here – only relative. Once that’s done, go back and name the pads! Any pattern works: [1 2 3 4 5], [TopLeft, MidLeft, BotLeft, TopRight, BotRight], [NW W SW SE NE], as long as you can tell which is which. Final image should look like something below.
- Spring '08
- Printed circuit board, EagleCAD