Smart devices shake up the connector world

Mobile devices, including smartphones and tablets, have become a disruptive technology that is shaking up the norms of system architecture. Traditional methods of introducing power and managing I/O are undergoing changes that are having major implications for traditional connectors. Read on to find out how.

Connectors of all types have been an integral element in the packaging scheme of electronic products for many years. Internal wire-to-wire, wire-to-PCB and PCB-to-PCB connectors allow designers to economically partition a system into manufacturable modules, which offer ease of repair as well as scalability. External connectors are used to introduce power and provide input/output signalling to the outside world.

Huge advances in semiconductor integration have enabled electronic equipment that is infinitely more powerful, even while shrinking from refrigerator-sized profiles to handheld portable devices. Products that required a daughtercard loaded with discrete devices can now be built around a single chip. The internal interconnections between board, power supply and display on many consumer products are often replaced by PCB traces on a single board, or a flex circuit.

Port density has become a major issue. We have watched as venerable I/O interfaces, such as the RS232 and Centronics connectors, were replaced by Firewire and USB connectors. These connectors not only offered increased port density, but also provided dramatically higher data transfer rates in a user-friendly profile. As devices become smaller, the space available for interconnection is reduced, which has spawned even smaller interfaces, including mini and micro versions of USB, as well as mini versions of DisplayPort and HDMI.  The new Thunderbolt interface from Intel does double duty in supporting both DisplayPort and PCIe technology.

Products that in the past sported a collection of different video, audio, power, headphone, daughtercard, memory, processor and peripheral connectors have been replaced by a few flex circuit connectors inside, and one or two micro USB external interfaces.

The consumer world is quickly moving away from the desktop and even the laptop computer towards mobile devices. A recent report indicated that personal computer sales plunged 14% in the first three months of 2013, nearly double the anticipated drop, while tablets and smartphones grew at double-digit rates.

Along with increased computing capability, silicon chips have been trained to consume dramatically less power. Not only does this facilitate tighter system packaging, but it also enables devices to cut their power cord tether and operate for hours using lightweight rechargeable batteries.

Short-range wireless communication is a perfect complement to these mobile devices and consumers are quickly adopting this technology. For example, the USB connector has served as the standard PC printer interface, but the majority of printers now feature a wireless link that eliminates a copper cable entirely.

Wireless charging pads using inductive coupling are becoming more common, again eliminating the power connector. Several concepts for wireless charging of vehicles have been proposed. A wireless charger built into the floor of a garage could safely recharge the batteries of an EV car while it is parked, with no intervention by the driver.

The ultimate solution would be to eliminate all external connectors, but that’s heresy among connector manufacturers and not very likely in the foreseeable future. Profiles would be unconstrained by a connector, and sealing the device against moisture and dust becomes easier. Reliability would be increased without the potential for failure that comes with an abused connector. Consumers would appreciate the reduced clutter and improved user experience. We may never get there, but wireless technology continues to whittle away at many standard I/O interfaces.

There is certainly no lack of short-range wireless technologies waiting to take the place of copper interfaces. Our homes are festooned with multiple remote controls that utilise infrared beams to control a host of consumer audio and video equipment. Additional wireless standards have been cropping up like spring weeds. Among the contenders:

• ANT+: proprietary wireless sensor networks.
• Cellular: Now being adapted for machine-to-machine applications.
• IEEE 802.15.4: Peer-to-peer links in industrial sensor networks.
• ISA 100A: Designed for applications in industrial process control.
• Wi-Fi, IEEE 802.11: Enables smartphones, laptops, tablets and video equipment to communicate with a local router.
• ZigBee: Often used in home automation networks.
• Bluetooth: One of the most widely adopted technologies, used in everything from automotive entertainment to headphones.

Worldwide shipments of integrated circuits that feature integrated Bluetooth are forecast to rise to 3.1 billion units by 2017, a 91% increase over 2011 shipments. Each of these technologies has established special interest groups that facilitate and promote the growth of their chosen protocol.

Building wireless connectivity into a device is becoming easier as complete transmitter and receiver modules are entering the market, freeing up product designers to focus on their product development. Systems on a chip (SOC) with integrated wireless connectivity are showing the greatest growth. The RFdurino, for example, is a finger-sized microcomputer with integrated Bluetooth communication capability.

The growth of wireless connectivity is likely to continue at even faster rates as it becomes easier to integrate this technology into new products. Microchip recently unveiled a major expansion of its embedded wireless modules that support Bluetooth, Wi-Fi and ZigBee. These drop-in assemblies consume very little power and quickly enable short-range or internet access. Some of these device suppliers offer a progression of capabilities to provide a footprint-compatible migration path to greater functionality.

The advent of cloud computing reduces the need for computational horsepower in the mobile device with access to applications available as needed and almost unlimited storage in the cloud. This reduces the need for large internal storage capacity. We may be returning to the era of dumb terminals.

Emerging wireless technologies, such as millimetre waves, continue to be introduced as demand for bandwidth-intensive applications increases. Innovative devices that operate in the 30 to 300 GHz frequency spectrum are used to provide a wireless short-range link among multiple devices, including set-top boxes, HDTVs, DVD players, game boxes, HD projectors and laptop computers.

Industrial automation and control is another area where wireless communication among sensors can reduce the copper infrastructure in process control applications. Banner Engineering recently introduced a completely self-contained wireless photoelectric sensor that features an integrated battery and radio. These sensors eliminate the need for an external power source as well as I/O signal cabling. Systems can be quickly reconfigured without costly wiring changes.

Near-field communications (NFC) is another area currently under intense investigation. These RF links differ from others in their ability to exchange relatively small packets of information in a burst mode over very short distances, typically less than 10 cm. A series of standards that define NFC communication in smartphones and similar devices are based on RFID (radiofrequency identification) technology. Devices must only be in close proximity or touch in order to automatically establish a contactless transaction. During initiation of a link, an RF field is generated that can power a passive receiver, such as tags, key fobs or credit cards, which do not require a battery. Peer-to-peer communication between two NFC-enabled devices is also part of the specification.

The initial target applications that were focused on mobile payment also envisioned smart car keys, security access cards and ID cards. A single NFC card was forecast to replace the wallet and could be used in all e-commerce exchanges. The NFC-enabled credit card has experienced less than universal approval in the United States, as hackers demonstrated the ease by which these cards could be read by simple scanners. Other applications related to social networking and ticketing installed on smartphones have been more successful. Friends need only tap their phones together to share photos, videos and contacts.

We are starting to see a form of wireless connectivity being explored. TE Connectivity recently announced the ARISO contactless technology platform, which utilises its expertise in magnetics, RF transmission and antennas to create an inductively coupled near-field interconnect.

Data signals and power can be transmitted across a gap of a few millimetres between the ‘mating’ connector faces. Initial applications are seen where voltage isolation, mechanical rotation or explosive environments make conventional connectors impractical.

There is little doubt that consumers want mobile access to the full array of communication, entertainment and information that has traditionally been tied to a wire. Mobile devices have shrunk in size and weight, leaving little room for traditional external I/O connectors. Wireless technology addresses that demand.

On one hand, the evolution to wireless connectivity will result in reduced volumes of what have become low-margin commodity connectors. On the other hand, the infrastructure consisting of thousands of cellular access points and supporting high-speed networks will require continuous upgrades in order to support increasing demand for bandwidth. We are now only on the leading edge of what will become the ‘Internet of Things’, which includes machine-to-machine communications. The connectors typically used in this equipment provide high signal density, operate at multigigabit data rates and are designed for much higher levels of reliability. It is unclear exactly how long it will take for these trends to play out, but for sure times are changing.