Add monolithic power QFN-20 3x5mm
Created by: HubertD
This adds a footprint for what MonolithicPower simply calls "QFN-20", used for their integrated switching regulators such as e.g. the MPM3620(A) and the MPM3630
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Provide a URL to a datasheet for the footprint(s) you are contributing https://www.monolithicpower.com/pub/media/document/MPM3620_r1.1.pdf#page=24 -
If there are matching symbol or 3D model pull requests, provide link(s) as appropriate planning to do a 3D model, but not there yet -
Check the output of the Travis automated check scripts - fix any errors as required -
Give a reason behind any intentional library convention rule violation. No violation intended, but:
As clearly visible in the screenshot, Pins 4-5-6 and 7-8-9 form a common pad. Since these triples are used everywhere in the datasheet, I decided to create on larger pad (pins 5 and 8) and slightly overlapping adjoining pads (4/6, 7/9). Not sure if that is the best way to do it.
Further, I did not add pads for the never-ever-dare-to-connect pins 19 and 20. For once, they do not even have usable measurements in the drawing. Second, datasheet shows a keep-out area where these pins are. Third, the datasheet states: "ANY PCB METAL TRACE AND VIA ARE NOT ALLOWED TO CONNECT TO THIS AREA ELECTRICALLY OR MECHANICALLY". I guess it's best to draw the keep-out area, leave the Pins away and be able to use the copper for routing purposes (with solder-resist of course)