A ribbon cable also known as Multi Wire Planar cable is a cable with several conducting wires running parallel to each other on identical flat plane as a result the cable is widespread and flat. Due to its resemblance with ribbon the name Ribbon Cable is given to it. Ribbon cables are usually used in the internal peripherals in computers. In previous computer systems (such as the BBC App and Micro). The ribbon like shape interferes with computer’s cooling system by disrupting airflow within the case and also makes the cables difficult to switch, particularly when there are a lot of them; as a consequence, round cables have almost entirely interchanged the ribbon cables for external connections and are gradually being used internally as well. Typical Ribbon Cable with connector is shown in figure.
The main purpose of ribbon cables is to permit mass termination to especially designed IDC connectors in which the ribbon cable is required onto a row of sharp forked contacts. Most commonly termination is done at each end of the cable. General varieties of connectors are available with IDC termination and are suitable for ribbon cable which are:
- Micro Ribbon
- DIN 41612
- BT224 Connector
- PCB transition headers
And DIL headers are also used occasionally when needed. For a ribbon cable with 26AWG wire, 0.05 inch spacing and common PVC insulation the resultant impedance for any two adjacent wires within the cable should be 110Ω to 130Ω. Information regarding impedance is one step toward understanding and control of external interference which might be caused by ribbon cables.