Add component TQFP48-EP to schematic

Schematic
1

Trying to add this component to a schematic (it’s a TMC5130 stepper driver chip)

https://www.trinamic.com/fileadmin/assets/Products/ICs_Documents/TMC5130_datasheet.pdf

Is the best approach to start with a TQFP-48 and modify or am I missing something here? I see the footprint in the libraries. Perhaps there is another package name I should be searching under?

Thanks

Adam

2

The schematic uses “symbols”,
the board layout uses “footprints”; and a TQFP48 is a “footprint”.

Take a look at page 121 of the datasheet link you provided. Since I don’t normally use parts with that many pins I normally make the symbols manually myself.

3

Trinamic have an example project in Eagle, https://github.com/trinamic/TRAMS, I extracted the relevant Trinamic library and converted it to KiCad.

I can’t vouch for the quality, but it might be a useful starting point. Trinamic.zip (4.2 KB)

4

The footprint is already in the lib. Have a look at TQFP-48-1EP_7x7mm_Pitch0.5mm in Housings_QFP.

For the symbol starting with the one provided by @bobc seems to be the best option. (Simply change the pin number for the exposed pad to connect to the exposed pad in the housings_qfp footprint.)

The footprint provided by @bobc has silk below the part. (could create problems while soldering)
There are also features on the fab layer that can not be selected in kicad. (polygons)
And there is also a strange copper feature that i can not select in the footprint editor.
It is also missing the courtyard definition. (And a reference on fab)

5

Eagle is much more flexible when it comes to layers and objects, so it can be tricky converting to KiCad. Wires and polygons can appear anywhere, and they are interpreted according to context. To add to the fun, polygons in Eagle can contain arcs.

In some cases Eagle features can be converted to a KiCad equivalent, e.g. polygons on copper layers can be converted to zones, but the conversion isn’t always ideal. I took the compromise of trying to retain as much info from the Eagle object as possible, with conversion to native features that work as expected in KiCad.

The fab layer I am not so worried about, I regard it as documentation only. I guess the strange copper features are in the “_RHINO” version? They have added traces to connect the EP, there are not really supported in KiCad but sort of work.