If it's Tuesday this must be Belgium.......
NC stands for No Connect. Here in Rio Linda that means not to connect them to anything.............
Sometimes access to test points on an IC are via such " extra "pins. If you want the exrtra real estate for traces cut them off. BTW great waffles man........
NC stands for No Connect. Here in Rio Linda that means not to connect them to anything.............
Sometimes access to test points on an IC are via such " extra "pins. If you want the exrtra real estate for traces cut them off. BTW great waffles man........Attachments
I would prefer to not clip the pins off of the chip, and leave them on to offer the chip better support, with respect to the connection from the pcb to the chip.
Then, on the pcb layout, the pins are simply not tied to anything.
This worked out quite well on my LM3875 layout. The chip sits much better with all the pins attached.
Another issue, is that the pins on the LM4780 are so small, and I would be afraid that I would cut off too many, or the wrong ones. I bought a few from Digikey, and am going to try to make an amp with them in the future.
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Brian
Then, on the pcb layout, the pins are simply not tied to anything.
This worked out quite well on my LM3875 layout. The chip sits much better with all the pins attached.
Another issue, is that the pins on the LM4780 are so small, and I would be afraid that I would cut off too many, or the wrong ones. I bought a few from Digikey, and am going to try to make an amp with them in the future.
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Brian
Maybe I can check for ESD diodes first. In most cases there would be some kind of ESD protection between the supplies and in- or-output-pins. If there is an open circuit that would mean the pin is not a TP.
I too prefer to keep all the pins attached. In some cases the stress from cutting off some pins is too much for the leadframe and can damage bond-wires of neigbouring pins. Atleast that's yhe case with smaller packages. I don't have any experiance with this type of package but I will not risk it.
Also the comment about stability is very true.
...yeah we do have tasty waffles here in Belgium.....ever tried some real Belgiun "frieten"? (The best French fries are not French
)
I too prefer to keep all the pins attached. In some cases the stress from cutting off some pins is too much for the leadframe and can damage bond-wires of neigbouring pins. Atleast that's yhe case with smaller packages. I don't have any experiance with this type of package but I will not risk it.
Also the comment about stability is very true.
...yeah we do have tasty waffles here in Belgium.....ever tried some real Belgiun "frieten"? (The best French fries are not French
)
rho said:I too prefer to keep all the pins attached. In some cases the stress from cutting off some pins is too much for the leadframe and can damage bond-wires of neigbouring pins. Atleast that's yhe case with smaller packages. I don't have any experiance with this type of package but I will not risk it.
Also the comment about stability is very true.
...yeah we do have tasty waffles here in Belgium.....ever tried some real Belgiun "frieten"? (The best French fries are not French
Yeah, keeping all the pins really helps for stability. Man, I was looking at the LM4780, and there are 27 pins, and only 7 of them are NC pins, so I don't think that it is worth the effort to get rid of 7 pins. They all look the same, and with the close spacing, there would be a good chance of cutting off the wrong pin. Also, you made a good point about the bond wires, I didn't consider that.
I was in Belgium a couple of summers ago, and I did have some French Fries and Waffles, and they were quite good.
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Brian
I had a closer look at the demo-board and all the NC-pins seem to be connected to eachother. The net seems to be floating.
I read the datasheet but I can not find any info on the NC-pins. I know that in some cases these pins are test-pins for the manufacturer. But it's not clear to me if they are in this case.
I read the datasheet but I can not find any info on the NC-pins. I know that in some cases these pins are test-pins for the manufacturer. But it's not clear to me if they are in this case.
I bet Paulb has never heard
of the Atomium and
Callebaut and Cote D'or and
a 3/4 mile street (Pelikaanstraat) in Antwerp where the world's epicentre lays of diamonds and gold, and
let's not forget the strangest, weirdest and most laughed at monument on this earth Manneke Pis in Brussels: a 3ft statue of a male standing on a pedestal facing tourists from all over the world that look at him while he is peeing..... in their direction, (says something about all those other nationalities, if you ask me, that come from 1000nds of miles away to get a glimps of this monument and.....
well there is so much to be seen I would go on and on and on
J-P
paulb said:
of the Atomium and
Callebaut and Cote D'or and
a 3/4 mile street (Pelikaanstraat) in Antwerp where the world's epicentre lays of diamonds and gold, and
let's not forget the strangest, weirdest and most laughed at monument on this earth Manneke Pis in Brussels: a 3ft statue of a male standing on a pedestal facing tourists from all over the world that look at him while he is peeing..... in their direction, (says something about all those other nationalities, if you ask me, that come from 1000nds of miles away to get a glimps of this monument and.....
well there is so much to be seen I would go on and on and on
J-P
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