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Low Power Design

17 posts
My last post dealt with designing your product to get long battery life. The title implied it was about primary batteries but in reality most of what I wrote would apply to get the best efficiency from any power source.  This week I’m going to continue in a similar vein but with considerations for using rechargeable batteries.   Read the complete post at http://cmicrotek.com/wordpress_159256135/. ...
Myths and legends are usually the subject of incredible beauty, unsurpassed strength or attempting what mere mortals assume is an unobtainable goal. It is often difficult to separate myth from reality or even know where one ends and the other begins. The same can be said for much of what you read these days about products with a 10 year battery life. When you see advertisements for wireless devices claiming 10 year battery life from a coin-cell battery it is easy to think that is the stuff of my ...
mlease

Keep it cool - part 2

Posted by mlease Jun 23, 2015
You may not expect to read about multiple amp loads in the context of “Low Power Design”. It could be an indication of how wide-spread the push for energy efficient products has become.  In many embedded applications it is quite common for a micro drawing a few milliamps to control motors or solenoids that require several amps of current or high-brightness LEDs that draw several hundred milliamps. Even if these current ranges are way above what your design has to deal with, the ...
mlease

Keep it cool!

Posted by mlease Jun 15, 2015
Several of my recent posts have mentioned the very negative impact of heat on power consumption. This is the first of a two part series of posts on thermal management for low power devices. This information is mostly taken from my "Low Power Design" PDF e-book. As semiconductor geometries have shrunk, in recent years leakage current has become a significant component of the overall power consumed by ICs. As parts heat up, their leakage current typically increases. It is not uncommon for par ...
I came across a mention in a newsletter recently of the Texas Instruments line of FRAM based MSP430 microcontrollers and thought a short post on FRAM would be of interest.   If you aren’t familiar with FRAM (also called FeRAM), think of it as essentially a non-volatile SRAM. FRAM was commercially developed primarily by Ramtron International starting in the mid 1980s.   Read the complete post at http://cmicrotek.com/wordpress_159256135/. ...
This post will focus on “current leaks”, the points of power consumption that are often designed into a device without much thought. In some cases they are things you have some amount of control over, in other cases they are things you have little control over but have to account for in your power budget in order to get an accurate power consumption or battery life estimate. While technically not leaks as in leakage current, I call them leaks because they are where your battery life ...
Last week was incredibly busy so I wasn’t able to put the time in to complete the third part of the “Leakage currents & current leaks” post. This will be a short post with a link to a white paper on our website for more details.   Most engineers consider the oscilloscope their first tool of choice for hardware development work. Yet very few engineers ever consider how accurate their scope is. Most of the major oscilloscope manufacturers place great importance on the t ...
Virtually all semiconductor devices have some amount of leakage current. It is interesting to note as operating voltages and device power consumption keep dropping, leakage current is becoming a larger percentage of a device’s power consumption. In most cases there isn’t much you can do about leakage currents other than be aware of them and account for them in your power analysis. In some cases there may be a significant difference in leakage current levels from manufacturer to manuf ...
Accounting for all of the obvious points of power consumption and their current levels for active and sleep states can be a difficult task. In every design there are also points of power consumption that are often overlooked. Every type of semiconductor device has some amount of “leakage current” that may or may not be called out in its datasheet.  Leakage current can make up the majority of the deep-sleep current draw for a modern micro when it shuts off power to most of its in ...
The CMicrotek µCP100/µCP120 are ideal for engineers developing wearable/portable devices, wireless "IoT" devices and energy harvesting powered devices. The µCP100 features a current range from 5nA to 100mA, the µCP120 is targeted at higher power applications such as WiFi with its 50nA to 800mA range.  With a voltage range from millivolts up to 20VDC they can be used with all of the common logic power supply voltages and small battery technologies. The µCP100/&m ...
It's been a while since I posted last but I plan to start doing that regularly again. We are now offering the “Low Power Design” PDF e-book for free on our website. I'll continue to cover low power design here along with relevant industry news and some occasional CMicrotek news.   So, about the e-book. Most of the information on the web about low power design focuses on hardware design (and mostly the same basic information repeated over and over) yet the firmware will often de ...
It’s been a few crazy busy months at work but I should be getting back on track with regular postings next week. This week I just have a few things that might be of interest ...   First, my company started a crowdfunding campaign on Indiegogo last week. We have working prototypes of our µPower Analyzer and µCurrent Probe and need help to ramp up production of the µCurrent Probe. We’re offering pre-orders on both products at a 20% discount. We also have a lo ...
mlease

C switch statements

Posted by mlease Oct 24, 2013
This week I covered several approaches to make large switch statements execute faster and save power. Switch statements are a great way to help keep your code readable but it is easy to forget they can turn into a long sequence of if-then-else statements.   http://cmicrotek.com/wordpress_159256135/?p=156 ...
I started getting into the detailed level about low power firmware design. There are many ways firmware can waste power and most of them are things you never even think about.   http://cmicrotek.com/wordpress_159256135/?p=151 ...
This week I'm continuing with some of low power firmware concepts. It may seem counterintuitive but some of the concepts I've used for low power firmware are the same things I did for the firmware on high performance disk controllers. To a large degree, whatever you can do to make your firmware run quicker will also make it more power efficient.   http://cmicrotek.com/wordpress_159256135/?p=138 ...