8 important references for connector selection

There are a wide range of commonly used connectors, from D-type connectors to frequently used connectors, there are 6 categories. Although there are many types, its selection needs to follow the following 14 points, mainly including on-load flow, impedance matching, shielding, versatility, cost, availability and other 14 standards.

1. Current load: When choosing the connector with the power signal, pay more attention to the current load of the connector, and use the derated design, while paying attention to the insulation voltage between the pins.

2. Structure size: the dimensions of the connector are very important, and the connections in the product have certain space limitations, especially the connectors on the single board, which cannot interfere with other components. According to the use of space, the installation location to choose the appropriate installation method (installation front installation and after installation, installation fixing methods such as rivets, screws, fasteners or connector itself pin fast locking) and shape (straight, curved, T, round, square).

3. Impedance matching: Some signals have impedance requirements, especially RF signals, which are more stringent for impedance matching, and impedance mismatch will cause signal reflection, thus affecting signal transmission. General signal transmission has no special requirements for the impedance of the connector.

4. Shielding: With the development of communication products, EMC has received more and more attention, the choice of connectors need to have a metal shell, while the cable needs to have a shielding layer, the shielding layer should be connected with the metal shell of the connector to achieve the shielding effect, you can also use the injection molding method, the plug part is wrapped with copper, the cable shielding layer and copper welding together.

5. Anti-misinsertion: anti-misinsertion has two aspects: on the one hand, the connector itself, the connector itself rotates 180 degrees, the wrong connection causes the wrong connection of the signal, at this time, it is necessary to pay attention to choose the anti-misinsertion connector as much as possible, or by adjusting the relative position of the connector to make the assembly unique; On the other hand, in order to reduce the types of materials, several signals are using the same connector, at this time it may appear to plug A into the B plug, at this time it is necessary to pay attention to, if this situation will cause serious consequences, you must choose A, B interface for different types of sockets.

6 Reliability: The connector is used to connect the signal, so the connection part should be reliable (such as surface contact is better than point contact, pinhole type is better than blade spring type, etc.).

7. Versatility: In the selection process of connectors, as far as possible to choose common objects, especially between the same series of products, the choice of connectors has a strong versatility, reduce the type of materials, increase the number to reduce costs, while reducing the risk of supply.

8. Use environment: When the connector is used with outdoor, indoor, high temperature, high humidity, salt spray, mold, cold and other environments, the connector has special requirements.