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