Short-range wireless links help eliminate the need for mechanical connectors

By Richard Quinnell, editor-in-chief

When
Apple debuted its iPhone 7, it dropped the headphone jack and eliminated with it
the space and placement, mechanical wear, and case penetration issues that come
with using the connector. Now the same benefits are set to come to USB 3.1,
USB 2.0, and I2C connections. Lattice Semiconductor is releasing a module that uses
12-GHz wireless for short-range, high-speed communications over a connector-less
interface.

The
Lattice Snap module is based on the company’s SiBEAM 60-GHz wireless
technology, which supports two full-duplex 6-Gbps communications channels on a
single wireless link. The radios involved are very low-power, giving them an
effective range of only a few millimeters, but that is enough to allow the link
to operate through a device’s case material and create a connection without
requiring an opening in the case or the use of conductive fingers and pads. The
target applications include connector replacement in mobile devices, laptops,
and the like.

The
concept is to use magnets to hold inside and outside Snap units aligned and
close together but with no electrical connection. Snap modules are available
with edge-fire and broadside radiation patterns, allowing connection placement
either on the edge or on the surface of a device. A USB cable replacement or
docking port, for instance, might use an edge connection point while a
surface-mounted accessory device such as a camera might use a broadside
connection. Either way, the result is a robust, high-speed data link that lacks
the mechanical wear and tear of pin-and-socket connectors, occupies a much
smaller profile than standard connectors, and permits device electronics to
occupy an environmentally sealed enclosure.

Lattice-Snap-Module

The
new Snap modules aim to simplify design-in of the wireless links. Host adapters
built into the modules support USB 3.1, USB 2.0, and I2C in either slave or master operation. Antennas are also built-in, and the modules have been
pre-certified for compliance with regulatory requirements in multiple
jurisdictions. They also include built-in power regulation so that all the developer
needs to do is connect 3.3-V power and the USB signal — no special software
required. When an initiator and a responder are brought together, the modules
automatically establish a connection that looks to the system just like a cable
plug-in.

The
modules also reduce the design-in effort by mitigating the critical RF signal
design effort. The Snap transceiver chip is mounted on a small PCB that
includes the crystal and power management. The PCB uses an optimized stack-up
to help eliminate crosstalk and provide EMI shielding at the module level. In
addition, the PCB is sized such that the designer simply cannot place other
system chips close enough to the module’s sensitive RF sections to create
signal integrity problems.

Advent of these Snap modules may well represent
another step that systems are taking away from reliance mechanical plug-in
connectors. With the headphone jack gone, wireless charging on the rise, and
now the USB connector gone wireless, all the holes in device enclosures are
getting filled in.