Electronics Components: Integrated Circuit Packages
Integrated circuits (ICs) come in a variety of different package types, but nearly all of the ICs you’ll work with in hobby electronics come in a type of package called dual inline package, or DIP.
Yes, the phrase “DIP package” is redundant because the P in DIP already stands for package, but the phrase “DIP package” is commonly used. Some justify this usage by claiming that the P actually stands for pin, so there’s no redundancy. But that’s just easy rationalization. Like it or not, DIP stands for dual inline package, and the phrase “DIP package” is commonly used and considered correct. Get used to it.
The phrase “DIP chip” is also sometimes used to describe ICs in DIP packages. It has a nice ring to it and sounds like something you would serve at a Super Bowl party.
A DIP package consists of a rectangular plastic or resin case that encloses the IC itself, with two rows of pins on the long sides of the rectangle. The pins on each side jut out a bit from the case, then turn straight down. This arrangement makes the package look like an insect.
In fact, one common way of wiring circuits that use DIP chips is to glue them to a board upside down and solder wires directly to the pins; this technique is called dead-bug wiring.
The pins on each side of a DIP package are spaced exactly 0.1″ apart, and the two rows of pins are usually spaced 0.3″ apart, though some larger DIP packages may have wider spacing.
The standard tenth-of-an-inch spacing is perfect for use with solderless breadboards, which have holes spaced at 0.1″ intervals. In fact, the gap that runs down the center of a solderless breadboard happens to be 0.3″, which makes it easy to mount DIP chips such that they straddle the gap.
Each pin in a DIP package is numbered. Looking down on the package from above, and you’ll see an orientation mark, usually a notch, groove, or dot.
Orient the package so that this mark is on the top, and pin 1 is immediately to the left of the mark. The pins are numbered counter-clockwise, working down the left side and then back up the right side until you get to the last pin, which is immediately to the right of the orientation mark.
The DIP package is for an eight-pin DIP. Larger DIPs have more pins, but the numbering scheme is always the same: Pin 1 is to the left of the orientation mark, and the remaining pins are numbered counter-clockwise from pin 1.