IoT sensors can run at lower power with MIT chip design
- 24 February, 2015 09:54
As more sensors get added to the Internet of Things, power consumption can pose a problem, but researchers at the Massachusetts Institute of Technology have come up with a way to reduce the energy that such components require.
The researchers have created a new circuit design that could lead to more power-efficient sensors, which are driving growth in the Internet of Things (IOT). About 1.2 billion IOT devices receive or transmit data wirelessly for alerts or analysis, and the number could grow to 5.4 billion by 2020, according to a study by Verizon.
Many sensors remain idle most of the time and become active when they send or receive data. The researchers have designed a circuit for a transmitter that could reduce energy leakage by up to 100 times when a sensor is in that idle state. That could extend the battery life of sensors by many months.
Wireless technologies are becoming more power-efficient but can still be one of the biggest electricity hogs in small devices. The new design doesn't compromise on wireless connectivity; it can generate enough power to transmit data using Bluetooth or the 802.15.4 specification, which is the basis for the Zigbee protocol.
The new circuit design reduces transistor leakage by passing a negative charge through a set of capacitors and switches during idle time. The negative charge effectively banishes electrons from the electrical leads, reducing the conductivity of the silicon and also the opportunity for leakage.
The MIT team tested a chip based on the new design and found it used only 20 picowatts of power to save 10,000 picowatts that would otherwise have been lost to leakage.
The research was led by Anantha Chandrakasan, a professor of computer science at MIT. He's also researched technology that could self-power IOT devices by drawing energy from body heat, solar energy or ambient surroundings. The new transmitter design could complement the energy-harvesting technologies to make IOT devices more power-efficient.
MIT did not say when the technology would reach chips. However, a test chip was manufactured by Taiwan Semiconductor Manufacturing Co. (TSMC), indicating the chip design is practical for fabrication. A paper on the technology is being presented at the International Solid-State Circuits Conference in San Francisco.