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Placing a caps as close as possible to a chip

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Screech

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So, I ve been advised to place caps as close as possible to Ic's.
These are 100nf caps, for decoupling, I guess.

How do I do it?

A Place the cap as close as possible to the positive pin.
B Place the cap as close as possible to the negative pin.
C Place the cap half way between the positive and negative pins.
 

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what matters i think is not how close it is to the +ve or -ve pins put the absolute length of the capacitor leads. the aim is just to reduce the inductive effect of long leads.
 
As a general "style" recommendation, I'd put that cap right on the end of the top of the chip, its pins would be closest to 1 and 14 of the IC. Just seems more natural and easy to recognize when placing. If you do it consistently then it's an obvious cue to which direction to orient the IC.
 
I could have drawn many combination but, I'm just trying to find out what works best, electronicly, if i had to pick 1 of the 3 pictured.
 
Hiya Screech,
I agree with Nigel on this, but when I use any dip component I always use a socket for the chip and I usually put a decoupling cap inside the socket and solder the cap to the socket before I solder the socket to the board. I found this tip ages ago on the net and found it to be handy. Off memory you can get sockets with caps already installed.

Cheers Bryan :D
 
For generic purposes, any of the 3 schematics can be used. However, if capacitance is such an important issue (like if you were doing an RF circuit), and you wanted the lowest capacitance and inductance, you want to create the shortest path. The easiest way for the shortest path is to connect one pin of the capacitor to the VCC pin of the IC, and the other pin to GND pin of the IC. you can make tracks go under the IC as well.
 
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