Featured Research

from universities, journals, and other organizations

New Analog Circuits Could Impact Consumer Electronics

Date:
February 19, 2007
Source:
Massachusetts Institute of Technology
Summary:
Advances in digital electronic circuits have prompted the boost in functions and ever smaller size of such popular consumer goods as digital cameras. But the same cannot be said of the older analog circuits in the same devices, which process natural sights and sounds in the real world. They are draining power and causing other bottlenecks in improved consumer electronic devices. Now MIT engineers have devised new analog circuits they hope will change that.

MIT professor Hae-Seung Lee and his colleagues have developed new analog circuits -- comparator-based switched capacitor circuits -- that handle voltage differently than conventional analog ones, resulting in greater power efficiency. (Credit: Photo by Donna Coveney)
Credit: Photo by Donna Coveney

Advances in digital electronic circuits have prompted the boost in functions and ever- smaller size of such popular consumer goods as digital cameras, MP3 players and digital televisions. But the same cannot be said of the older analog circuits in the same devices, which process natural sights and sounds in the real world. Because analog circuits haven't enjoyed a similar rate of progress, they are draining power and causing other bottlenecks in improved consumer electronic devices.

Now MIT engineers have devised new analog circuits they hope will change that. Their work was discussed at the International Solid State Circuits Conference (ISSCC) in San Francisco Feb. 11-15.

"During the past several decades engineers have focused on allowing signals to be processed and stored in digital forms," said Hae-Seung Lee, a professor in MIT's Microsystems Technology Laboratories (MTL) and the Department of Electrical Engineering and Computer Science (EECS). "But most real-world signals are analog signals, so analog circuits are an essential part of most electronic systems."

Analog circuits are used to amplify, process and filter analog signals and convert them to digital signals, or vice versa, so the real world and electronic devices can talk to each other. Analog signals are continuous and they vary in size, whereas digital signals have specific or discrete values.

The reason the two different types of electronic signal circuits did not advance at the same pace, Lee said, is because they are very different. Digital circuits can be decreased in size more easily, for example, by using the popular complementary metal oxide semiconductor (CMOS) technology. And much of the design and performance enhancement can actually be done by computer software rather than by a human. That's not the case with analog circuits, which Lee said require clever designs by humans to be improved because of their variable nature.

"There is a lot of room for innovation in the human design," he said. "The importance of analog circuits is growing in light of the digital improvements, so engineers can make a difference in products by working on them." Currently, analog circuits are rather expensive and they consume a disproportionate amount of power compared with digital circuits.

Another blow to analog circuits is that the advancements in fabrication (manufacturing) technology to improve digital circuits have had a negative impact on them. Traditionally, many conventional analog circuits have relied upon devices known as operational amplifiers. Two negative side effects that advanced fabrication technologies have had on operational amplifier-based analog circuits are that when used in consumer or other devices, they have reduced the range of the analog signal and decreased the device's gain. To compensate for these shortcomings, analog circuits must consume much more power, thus draining precious energy from batteries.

In addition, it still is not clear whether traditional operational amplifier-based circuits can be applied to emerging technologies such as carbon nanotube/nanowire devices and molecular devices.

Lee's research group, in collaboration with Professor Charles Sodini's group in MIT's MTL and EECS, recently demonstrated a new class of analog circuits that Lee said eliminates operational amplifiers while maintaining virtually all benefits of operational amplifier-based circuits. These new comparator-based switched capacitor (CBSC) circuits handle voltage differently than conventional analog ones, resulting in greater power efficiency.

"The new work coming out of MIT offers the intriguing possibility of eliminating operational amplifiers by proposing an architecture that relies on circuit blocks that are much more readily implemented on supply voltages of 1 volt or less," said Dave Robertson, high-speed converter product line director at Analog Devices Inc. in Norwood, Mass., and data converter subcommittee chair at ISSCC.

Lee said CBSC may enable high-performance analog circuits in emerging technologies because it would be easier to implement comparators than operational amplifiers in these technologies.

The first prototype MIT CBSC was demonstrated in an analog-to-digital converter and presented at 2006 ISSCC. The second prototype, an 8-bit, 200 MHz analog-to-digital converter, will be presented at the conference this month.

Other key members of the research team are EECS graduate students John Fiorenza and Todd Sepke, who were involved in the work presented in 2006; EECS graduate student Lane Brooks, who worked on the current prototype; and Peter Holloway of National Semiconductor Corp.

The research leading to the 2006 ISSCC paper was funded by Microelectronics Advanced Research Corp. The research leading to the paper presented this month was funded by the MIT Center for Integrated Circuits and Systems and a National Defense Science and Engineering Graduate Fellowship.


Story Source:

The above story is based on materials provided by Massachusetts Institute of Technology. Note: Materials may be edited for content and length.


Cite This Page:

Massachusetts Institute of Technology. "New Analog Circuits Could Impact Consumer Electronics." ScienceDaily. ScienceDaily, 19 February 2007. <www.sciencedaily.com/releases/2007/02/070218135408.htm>.
Massachusetts Institute of Technology. (2007, February 19). New Analog Circuits Could Impact Consumer Electronics. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2007/02/070218135408.htm
Massachusetts Institute of Technology. "New Analog Circuits Could Impact Consumer Electronics." ScienceDaily. www.sciencedaily.com/releases/2007/02/070218135408.htm (accessed September 19, 2014).

Share This



More Matter & Energy News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

MIT BioSuit A New Take On Traditional Spacesuits

MIT BioSuit A New Take On Traditional Spacesuits

Newsy (Sep. 19, 2014) The MIT BioSuit could be an alternative to big, bulky traditional spacesuits, but the concept needs some work. Video provided by Newsy
Powered by NewsLook.com
Virtual Reality Headsets Unveiled at Tokyo Game Show

Virtual Reality Headsets Unveiled at Tokyo Game Show

AFP (Sep. 18, 2014) Several companies unveiled virtual reality headsets at the Tokyo Game Show, Asia's largest digital entertainment exhibition. Duration: 00:48 Video provided by AFP
Powered by NewsLook.com
Apple's iOS8 Includes New 'Killswitch' To Curb Theft

Apple's iOS8 Includes New 'Killswitch' To Curb Theft

Newsy (Sep. 18, 2014) Apple's new operating system, iOS 8, comes with Apple's killswitch feature already activated, unlike all the models before it. Video provided by Newsy
Powered by NewsLook.com
Stocks Hit All-Time High as Fed Holds Steady

Stocks Hit All-Time High as Fed Holds Steady

AP (Sep. 17, 2014) The Federal Reserve signaled Wednesday that it plans to keep a key interest rate at a record low because a broad range of U.S. economic measures remain subpar. Stocks hit an all-time high on the news. (Sept. 17) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins