Phoenix Processor Sets New Lower Power Processing Record

Engineers at the University of Michigan have developed a new microchip that uses 30 picowatts in sleep mode, which roughly computes to 30,000 times less power in sleep mode and ten times less power when working than other comparable chips on the market.

The processor, called The Phoenix Processor could theoretically run on a standard watch battery for up to 200 years.

The processor isn’t physically any smaller than other chips on the market, what makes the Phoenix revolutionary is that its thin-film battery is the same size as the Phoenix chip. Typically batteries used with processors are much larger than the processor itself making the overall size of the device much larger. Engineers also used a little old school ingenuity, using much smaller power gates that let smaller amounts of electricity leak past the power gates when in sleep mode.

The draw back to smaller power gates is that they place sever limits on the processing power of the chip. To remedy this performance loss the researchers run the Phoenix at a higher operating voltage of about 20% greater than needed when the chip is awake. Despite the higher power sent to the chip when awake it still consumes only 0.5 volts. By comparison the Intel Atom processor needs 1.1V to operate.

U-M researchers built the chip with the major application coming for use in sensors. Thus the push for lower power consumption during sleep mode. "Sleep mode power dominates in sensors, so we designed this device from the ground up with an efficient sleep mode as the No. 1 goal. That's not been done before," said Dennis Sylvester, an associate professor in the Department of Electrical Engineering and Computer Science.

The system defaults to sleep. A low-power timer acts as an alarm clock on perpetual snooze, waking Phoenix every ten minutes for 1/10th of a second to run a set of 2,000 instructions. The list includes checking the sensor for new data, processing it, compressing it into a sort of short-hand, and storing it before going back to sleep.

The timer "isn't an atomic clock," Hanson said. "We keep time to 10 minutes plus or minus a few tenths of a second. For the applications this is designed for, that's okay. You don't need absolute accuracy in a sensor. We've traded that for enormous power savings."

A team of researchers has already been putting the Phoenix into biomedical sensors. They plan on building a sensor to monitor eye pressure in glaucoma patients. Engineers envision that chips like this could also be sprinkled around to make a nearly invisible sensor network to monitor air or water or detect movement. They could be mixed into concrete to sense the structural integrity of new buildings and bridges. And they could power a robust pacemaker that could take more detailed readings of a patient's health, researchers say.