PLC IC Shrinks Power, Comm Footprint in Wireless Earbuds

Feb. 5, 2020

True wireless earbuds and other wearables benefit from a tiny powerline communications IC that promises to save space, be more reliable, and simplify design-in compared with other approaches.

David Maliniak

Ultra-low-power portables and wearables need to both draw power from, and communicate with, a charging dock. With consumers demanding ever-smaller devices for their comfort and convenience, designers of portables and wearables look anxiously for ways to meet that demand. Enter Maxim Integrated Products with its MAX20340 2-pin, bidirectional dc powerline communications (PLC) IC, which can reduce the size of a power and communication interface to the charging dock by up to 80%, the company claims.

With power and communication on a single line, the MAX20340 eliminates pins and discrete devices needed to communicate between a charging dock and a low-voltage end product such as true wireless earbuds, biosensing rings, and other small wearables. This simplifies the design process and saves up to 13 mm² per earbud compared to the closest competitive solution.

The ultra-small (1.84 mm²) MAX20340 PLC chip minimizes the number of mechanical contact points for the charging and communication interface, which lowers cost, limits points of failure, and increases reliability. In addition, the IC incorporates automatic presence detection, enabling flexible design and eliminating unreliable and costly alternative methods like mechanical pogo pins or Hall-effect sensors. A single external resistor configures the device as either a communication master or slave. In addition, the chip requires no large external components such as inductors.

Multiple modes of operation offer designers the opportunity to minimize power consumption based on their application needs. Finally, the communication protocol is as elementary as reading and writing using a simple mailbox communication scheme via the I²C serial-data protocol—the PLC chip manages all communication across the interface.

The MAX20340 is available at Maxim’s website for $0.82 (1000-up, FOB USA), as well as from authorized distributors. The MAX20340EVKIT# evaluation kit goes for $57.

Maxim Integrated Products, www.maximintegrated.com

About the Author

David Maliniak | MWRF Executive Editor

In his long career in the B2B electronics-industry media, David Maliniak has held editorial roles as both generalist and specialist. As Components Editor and, later, as Editor in Chief of EE Product News, David gained breadth of experience in covering the industry at large. In serving as EDA/Test and Measurement Technology Editor at Electronic Design, he developed deep insight into those complex areas of technology. Most recently, David worked in technical marketing communications at Teledyne LeCroy. David earned a B.A. in journalism at New York University.