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Electronics => PCB/EDA/CAD => KiCad => Topic started by: vini_i on January 23, 2017, 11:17:28 pm

Title: Dual package OpAmp
Post by: vini_i on January 23, 2017, 11:17:28 pm

I want to use a dual package OpAmp. Looking at the available symbols, the dual OpAmps are split up into two individual symbols, which is typical. What I have not seen before is that both symbols have power and ground pins. The pin numbers are the same, 8 and 4 on both symbols. The other pin numbers change to reflect the two different OpAmps in the same package.

How should i treat the two sets of power and ground pins? Hook them both up or leave one set disconnected?

Title: Re: Dual package OpAmp
Post by: bson on January 24, 2017, 10:46:59 am

I have my own parts which only have power and ground on unit A.  Creating this is as simple as cloning the part and in unit A flagging the pins as not shared.

You might get away with only connecting them once, meaning DRC shouldn't complain, but personally it bugs me enough to see unconnected pins that I'd just create a new library part.

Title: Re: Dual package OpAmp
Post by: Dave_PT on January 24, 2017, 10:57:40 am

In principle you only need to connect the power pins to one of the parts.

I did this yesterday, on a test circuit, and I had no DRC errors...

Title: Re: Dual package OpAmp
Post by: james_s on January 25, 2017, 03:33:35 am

I often put voltage terminals on all of the power and ground pins, even though on the IC there is only one physical set of pins. It doesn't matter, you can just use one set or even one power pin on one unit and the other power pin on the other unit. I only use both because I think it looks neater.