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Can floating connectors solve your problems?

As electronic systems become smaller, the components that they use must keep pace. This may seem like an overly simplistic statement, but when it comes to connectors, miniaturisation poses a few key problems.

One of the key characteristics of PCB-mounted connectors is the pitch. The pitch of a connector describes the distance between the centre of one contact or terminal and the next. When I entered the world of connectors 26 years ago, many of the most common connectors used a pitch of 2.54mm, the metric equivalent of an old imperial measurement, 0.1 inch. This included the DIN 41612 connector family, and many of the most common ribbon cable connectors.

If we look at the components that will commonly be found on a PCB, we will see that connectors are one of the few components that actually need to interface mechanically with another device or PCB, and so it becomes important that the connectors are placed with a certain amount of accuracy. As electronic systems have grown smaller over the years, connectors have kept pace, and now it is common to find connectors with a pitch of well below 1.0mm.

As you can imagine, smaller pitch connectors can become difficult to plug in correctly. Not only does the small size of the connector require greater care when aligning the two mating halves, but the small scale of the connector can make them less robust and more susceptible to damage if not handled correctly. In addition, if the PCB connectors are not mounted in exactly the right place, the misalignment can cause greater problems. Figure 1 shows an example of a design where the two connectors, mounted incorrectly, prevent the entire device from being assembled correctly. Forcing the two halves of the device together might damage the termination.

Fig 1. 

One solution to this problem is to include a connector that can "float". A floating connector is deliberately designed to move slightly to accommodate the misalignment of its mating half - see figure 2.

Fig 2.  Moving or floating section (1); Fixed portion (2); Spring contacts (3)


The FunctionMAX family of connectors from Hirose includes a number of connector series with pitches of 0.5mm (FX10, FX20, FX22 and FX23) and 3.81mm (FX30B), all of which are designed to "float" to allow for misalignment. The fine pitch connectors are all designed for very high speed transmission (up to 15 Gbps in the case of the FX10), while the 13A to 19A current capacity of the FX30B functions as a power connector. As all are designed to float, these connectors can be used in conjunction with each other in a range of board-to-board designs, including parallel (mezzanine), edge-to-edge and right-angled configurations.

For a full guide to the features of the FunctionMAX family, click on the featured products or download the datasheet here.

Connector Geek is Dave in real life. After three decades in the industry, Dave still likes talking about connectors almost as much as being a Dad to his two kids. He still loves Lego too. And guitars.
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