i am designing a power amplifier pcb layout for the qpa4992 and in the pin description it is stated that the back side of the package should be connected to the ground. Please explain why this is done and how to do this kicad?
For why it is done, that is a question for the manufacturer. Probably thermals but only they know for sure.
Make sure that both your footprint and symbol have the pad on it with the same pin number. Just like all the other pins.
i am totally new to it, can you please explain it from basics?
I was a bit confused by Ti’s OPA4992 but your pin configuration matches the quorvo chip: https://www.qorvo.com/products/p/QPA9942
The Quorvo chip is an amplifier in the 3.5GHz range. HF stuff needs special considerations. That’s also why a 16 pad device has 9 GND pads. That’s no accident or “left over” pads, as bigger packages with more pads are more expensive to produce. This forum is (mostly) concerned with learning how to use KiCad. It’s not for learning electronics. There are other and better sources for that.
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okay please guide me further where can i head to do this.
Unless you’re less then 14 years old, you should be training your self reliance and confidence a bit. We don’t know what’s the best solution for increasing your electronics knowledge is. It can be anything from formal education, some online courses, reading some books, going to some electronics forums, or other resources on the internet.
Gathering random bits from various sources is not the most efficient way to learn electronics, but a formal education may be too involved / expensive. You’ll have to find some compromise that suits your personality / budget / interest / goals, etc.
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two things;
one is you can download the symbol and footprint directly from quorvo through samacsys (there’s ways of getting those into kicad, see some other fourm posts). ( that’s kicad related, in that it’s getting those imported into kicad. )
two, even though the manufacturer didn’t give the “back paddle” a number, you need to give it a number (usually the next highest one) and assign that number to the “pad” you make in the footprint. there are many examples of parts in the existing kicad libraries with and “EP” which is what quorvo is calling “back paddle”
here’s one example of a part that has several odd shaped pins under the part.
my $0.02 advice is; even if you start with the downloaded samacsys part, you should double check the pin numbering/naming for the symbol. and you should triple check the dimensions of footprint, pads, outline, clearance, etc. then you should save that in your own personal library.
good luck!