Breaking News
Comments
Newest First | Oldest First | Threaded View
Max The Magnificent
User Rank
Blogger
Re: Half speed
Max The Magnificent   5/29/2014 9:43:46 AM
NO RATINGS
@zeeglen: Once - and only once - I proposed similar.  The software people were like to have me strung up, drawn, and quartered for even THINKING such a heretical notion.

I recall a computer in the UK -- you could purchase one with a certain amount of computing power for a certain price -- when your company needed more computing power, you could pay for an upgrade.

The technician would come round and pull out your mother board and plug in a new "super duper" motherboard with "twice the computing power" -- once back in his van, he would take your old board and swap the jumper from 1X clock to 2X clock, then that was the "new" board he would take into the next company...

zeeglen
User Rank
Blogger
Half speed
zeeglen   5/29/2014 9:23:26 AM
NO RATINGS
From the article: Running the CPU at half the clock speed, for example, can halve its power consumption.

Once - and only once - I proposed similar.  The software people were like to have me strung up, drawn, and quartered for even THINKING such a heretical notion.

Seriously, this a very informative series of articles, came here from Part 3, don't know how I missed Parts 1 and 2 the first time around.

cuong@edadirect.com
User Rank
Rookie
Monitoring after the board is done is good but does the board have enough copper in the first place?
cuong@edadirect.com   4/25/2014 10:43:01 PM
NO RATINGS
This is a great post that should bring awareness to the board designers.  I'd like to supplement the article content by proposing that simulations of the PDN (Power Distribution Network) be done prior to board fab (and during layout) to ensure that there's enough copper in the plane (or thick traces) that need to accomodate high current switching activities.  In today's board design (specifically in the pwr/gnd plane structures) the designer needs to be aware that the pwr/gnd planes can be fragmented due to pin breakouts, via structures, narrow areas, etc...  As such, the full current-carrying effects of the planes cannot be realized.  There could be narrow areas (or neck-down) sections of the plane that must carry the required currents from the regulator to the destination devices.  These types of areas are the bottlenecks in the plane structures and can cause significant (and dynamic) voltage drops when there are high current switching activities from the device power pins connecting to the rail (or GND return paths).  The current will take the path of least resistance (ie. shortest path) to/from the voltage regulator so if these areas are not analyzed correctly there can be areas of high concentration of current density (mA/mil square) that potentially can heat up the traces causing breakdowns over time.  The idea is to have sufficient copper pours to minimize the DC drop (or loss) voltage.  The best way to fix the problem is to avoid it in the first place before the board is fabbed and components are stuffed.  The bench used to be my favorite place to spend time but nowadays I spend more time in simulations than sitting on the bench measuring things.  Simulations can identify issues before the board is fabbed...  Now where would you rather spend time (and money)?



Flash Poll
Top Comments of the Week
Like Us on Facebook
EE Times on Twitter
EE Times Twitter Feed

Datasheets.com Parts Search

185 million searchable parts
(please enter a part number or hit search to begin)
EE Life
Frankenstein's Fix, Teardowns, Sideshows, Design Contests, Reader Content & More
Max Maxfield

Energizing the Young Engineers of Tomorrow
Max Maxfield
15 comments
It doesn't seem all that long ago when I was a bright-eyed, bushy-tailed young engineer. Now I feel like an old fool, but where are we going to find one at this time of the day (LOL)?

Jolt Judges and Andrew Binstock

Jolt Awards: The Best Books
Jolt Judges and Andrew Binstock
1 Comment
As we do every year, Dr. Dobb's recognizes the best books of the last 12 months via the Jolt Awards -- our cycle of product awards given out every two months in each of six categories. No ...

Engineering Investigations

Air Conditioner Falls From Window, Still Works
Engineering Investigations
2 comments
It's autumn in New England. The leaves are turning to red, orange, and gold, my roses are in their second bloom, and it's time to remove the air conditioner from the window. On September ...

David Blaza

The Other Tesla
David Blaza
5 comments
I find myself going to Kickstarter and Indiegogo on a regular basis these days because they have become real innovation marketplaces. As far as I'm concerned, this is where a lot of cool ...