Small Connectors Deliver Big Functionality

Microprocessors may get all the glory, but at the heart of every handheld and wearable electronic product, there’s a tiny connector, delivering the power and signals.

And, these days, the need for those tiny connectors is growing. In products ranging from military radios and computers to medical staplers and hearing aids, miniaturized connectors are emerging as a key enabler. “It’s about packing more functionality into smaller boxes,” said Wim Vanheertum, product manager for Fischer Connectors. “That’s the challenge of design engineers today.”

Indeed, the challenge is for engineers to make their electronic packages smaller, which is why little connectors are coming up so big. Processors, no matter how powerful, can’t do that by themselves. That’s why a new breed of connectors -- some less than 10 mm across -- are serving as a solution for design engineers who want, or need, to shrink their products.

A case in point: Fischer recently helped downsize a miniature military computer by replacing 12 connectors with just four. Known as the M3-Lite from DTech Labs, the portable computer lost no functionality in the process. Engineers accomplished the reduction by incorporating MiniMax 08 connectors measuring just 12 mm in diameter. Each MiniMax connector contains 24 contacts -- four for power and 20 for signals. The four power contacts can handle up to 5A each. Fischer says the connectors are about 45% smaller and 75% lighter than predecessors in such applications.

“Power, screen USB, Ethernet -- all have been combined into four MiniMax connectors,” Vanheertum said.

In the Operating Room

The need for small connectors is also growing in the medical device industry. TE Connectivity, a maker of connectors for harsh environments, is seeing a growing demand for tiny connectors in products ranging from arthroscopic surgical devices and hearing aids to electromechanical staplers and even “smart” catheters for minimally invasive operations.

“The technology is evolving in all these areas and there’s a need for more signals and power then there was in the past,” noted Navin Patel, development engineering manager for TE Connectivity.

TE recently developed custom 5-mm-diameter connectors for a cordless electromechanical medical stapler. The connectors, made from a polymer known as Vectra, weigh just 0.18g. “It has
contacts for power and there’s also a small EEPROM chip used for authentication of the product,” Patel said.

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TE engineers say the connectors answer a need in medical staplers, particularly those that are moving from the traditional pure mechanical technology to the cordless electromechanical style. Those newer models have tighter space constraints and a greater need for minimal weight, according to Patel.

The connector’s EEPROM chip also added a measure of intelligence to the stapler. Cartridges containing different sizes and quantities of staples can now be recognized by the chip, enabling the stapler to reconfigure itself for the application.

Equally important, the EEPROM’s authentication capabilities could also serve in other medical devices, especially those that are vulnerable to counterfeiting. “There are a lot of liability concerns in the medical market,” noted Bill Irwin, product manager for electro-surgical products at TE Medical. “Having your system authenticated makes people more comfortable.”

On the Battlefield

Connector manufacturers say the smaller connector sizes weren’t readily available a few years ago, in part because there was little demand for such space-saving technology. But they’re beginning to see new applications springing up, especially in telecommunications, wearables, and handheld military devices.

Fischer, for example, has supplied connectors for military radios, night vision goggles, and smart sights on soldiers’ rifles. “We’re seeing an evolution in what’s being carried by soldiers,” said Vanheertum. “Radios, GPS systems, computers – they’re all getting smaller and they’re all getting more complicated.”

Military rifle sights are a prime example of the growing complexity. Today’s advanced sights may incorporate sensor-based information, such as wind direction, wind velocity, sunlight levels, and distance to target. Similarly, a soldier’s goggles may contain GPS systems or radios capable of transmitting data to distant locations. “We have different protocols coming together in smaller housings,” Vanheertum said. “That’s why people are looking for smaller connectors with more contacts, so they can have multiple protocols passing over one connection, if possible.”

For especially confined applications like those, Fischer offers its MiniMax 06, which squeezes 12 contacts (two for power, 10 for signals) in a 10-mm diameter. The company stresses the connector’s so-called “density factor” -- in other words, its ability to pack more contacts into a smaller footprint. The MiniMax 06 has a factor of 0.83 (10 mm/12 contacts), making it denser than today’s standard industry connectors. Announced in May 2016, the MiniMax 06 is being marketed toward wearable applications in defense, security, instrumentation, and unmanned aerial vehicles.

The trend toward smaller connectors, however, isn’t confined to handhelds and wearables. Molex, Inc., for example, recently rolled out a Micro-Fit TPA Single-Row Receptacle, which is targeted at applications such as signage, lighting fixtures, electronic games, and other products that similarly need to deliver power and signals to tight quarters. By design, the TPA connector series (TPA stands for terminal position assurance) is also aimed at applications that are vulnerable to terminal back-out, which could produce intermittent operation.

Recent applications for the Micro-Fit TPA include computer cooling fans for servers. “The fans need both power and signal feedback in order to monitor the operating status,” wrote Molex product manager, John Luthy, in an e-mail to Design News. “Customers will select a multi-pin part and use two of the connections for powering the fan and use the remaining connections to monitor it, and shut the fan down if it’s not rotating.”

Applications such as Molex’s may serve as proof that the trend toward miniature connectors is set to move beyond the realm of handhelds. As more products add to their electronic complexity, the demand for small size, low weight, and higher power connectors is likely to migrate to applications in telecommunications, computing, and automotive, as well as medical and military.

“In new generations of products, we’re seeing the incorporation of sensors and electronics,” noted Irwin of TE Connectivity. “So there’s always going to be a need to keep the parts small and the weight down.”

Senior technical editor Chuck Murray has been writing about technology for 32 years. He joined Design News in 1987, and has covered electronics, automation, fluid power, and autos.