In most DIP integrated circuits, two of the pins are used to provide electronic power to the circuit. One of these is designated for positive voltage, typically identified with the symbol VCC. The other is the ground pin. For example, the 555 timer chip requires a positive supply voltage between 4.5–15 V at pin 8, and pin 1 is connected to ground.

In the case of ICs that contain two or more separate circuits, the circuits usually share a common power supply. Thus, even though a 556 dual timer chip contains two separate 555 timer circuits, the chip has just one positive voltage pin and one ground pin.

Also, you should be aware that some integrated circuits call for separate positive and negative supply voltages, not just a positive and a ground connection.


When you build a circuit board that contains one or more integrated circuits, be careful that you don’t damage the IC when you build your circuit. In particular, you should watch out for these two possible problems:

  • Static discharge: Many integrated circuits can be damaged by static electricity discharged though your fingers when you handle the chips. As a result, make sure you discharge yourself by touching a grounded metal surface before handling an integrated circuit. You may also want to use an antistatic wristband when handling ICs.

  • Heat damage: Some integrated circuits are sensitive to heat, so you should take precautions whenever you solder an IC to a circuit board. If possible, attach an alligator clip or other type of heat sink to the pin to help dissipate some of the heat away from the IC itself.

    You can avoid soldering integrated circuits altogether by using DIP sockets. When you use these sockets, you solder the socket to your circuit board. Then, once the socket is safely soldered in place, you simply insert the IC into the socket.