Circular female pins are shown on the sockets, but square receptacles are also common.
Dual in-line Package, DIP.
Dual In-Line Package
Another common style of DIP socket accepts discrete components. This package style may also be called an Adapter Socket, because it adapts the discrete components into a 14-pin DIP out-line.
Dual In-Line Package
Some types of DIP sockets, normally open-frame sockets, have integrated by-pass capacitors already attached to the bottom of the socket frame. The capacitor is attached to the last pin of the left and right sides of the socket; pins 7 and 14 of a 14-pin socket or pins 8 and 16 of a 16-pin socket. In many logic families these are the ground and power pins of the IC.
Open Frame sockets allows for more efficient cooling by leaving the space between the Printed Wiring Board [PWB] and IC free for air flow.
Most DIP sockets are Side-to-side and end-to-end stackable.
Other DIP socket styles include right-angle sockets that allow the IC to be mounted either horizontally or vertically in the DIP socket, while the socket is at a right angle to the PWB.
Some DIP sockets also come with an ejector/latch so the IC can be secured in the socket and then easily removed.
Surface Mount DIP sockets are available, in addition to Low-Profile through-hole sockets.
DIP Adapters are also common and used as dropped in replacements for end-of-life DIP ICs. DIP Adapters convert one IC pinout into another, or surface mount to through-hole converters. Related pages; 8-Pin DIP through-hole style.
In addition to both the Open Frame and Closed Frame IC sockets shown, sockets may also be bolted down to the Printed Wiring Board [PWB]. The 14-pin Closed Frame IC socket shown to the left may be secured to the PWB with a nut and bolt. Bolting the socket down helps in high vibration conditions, of course having an IC in a socket may not do well on the shack table, but the socket is safe. Notice that the over-all size of the solid frame IC socket does not change. The open frame is in the same family of sockets and only shown for completeness.
As a general rule never use sockets in a design unless absolutely required. A socket adds one more line item to the parts list, one more part to be stocked and of course adds cost to the design. In addition a socket adds lead inductance to the terminals of the IC.
An increase in the inductance of a leads slows the rate of change in current through that lead, and slows the reaction of the device. Lead inductance also causes Ground Bounce, which induces noise or false switching in the IC, because a voltage is generated across the IC pin due to the inductance.
In addition to ICs and sockets there are also adapters that convert some other form factor to a DIP package, as in a DIP adapter. Refer to the IC Converter page which covers IC sockets [SMD to thru-hole]. There are also RC or Resistor Networks that are also found in a DIP package. A bit less common are IDC DIP connectors or adapters; that are a through-hole DIP component on the board side but also accepts a ribbon cable on the other side [cable to DIP]. MIL-DTL-83503/6 defines a 0.50 Flat cable connector to dual in-line plug [.100 X .300, .100 X .400, and .100 X .600 contact spacing], with 8, 14, 16, 18, 22, 24, 28, 40 pin contacts.