Tag Archives: battery

Ars Technica, Daily Mail and other media talk SAM L21

The new Atmel | SMART L21 is expanding battery life from years to decades. 

This week, Atmel revealed the big news that the recently-unveiled Atmel | SMART SAM L family consumes just one-third the power of existing solutions already on the market. Having achieved a 185 EEMBC ULPBench score, the SAM L21 is now the world’s lowest power ARM Cortex-M based device.

Impressively, the series boasts power consumption down to 35µA/MHz in active mode and 200nA in sleep mode. The SAM L not only broadens the company’s current 32-bit ARM-based MCU lineup, but extends battery life from years to decades, reducing the number of times batteries need to be changed in devices such as fire alarms, wearables, medical gadgets and equipment placed in rural, agriculture, offshore and other remote areas. The SAM L21 combines ultra-low power with Flash and SRAM that are large enough to run both the application and wireless stacks — three features that are cornerstones of most Internet of Things (IoT) applications. Sampling now, the SAM L21 comes complete with a development platform including an Xplained Pro kit, code libraries and Atmel Studio support.

The SAM L21 MCUs will enable designers to solve their power challenges for battery-powered IoT devices — something that has caught the attention of mainstream media outlets including Ars Technica, Gizmodo, The Register, Network World and Daily Mail, as well as industry journals like Silicon Republic, New Electronics and EE Times.

 Sean Gallagher, Ars Technica 

“The number of things getting plugged into the Internet of Things has already reached the point of satire. But there’s a new, extremely low power technology that’s being prepared for market that could put computing power and network access into a whole new class of sensors, wearables, and practically disposable devices. That’s because it can run off a battery charge for over over 10 years.”


“The processor may not be enough to, say, run an Ubuntu desktop, but it’s certainly enough computing power and memory to run a real-time operating system with multiple programs, handle physical interfaces, stream media from a USB device or other external storage, and tweet you when your dishes are clean. It also can handle a lot of tasks that can reduce the power usage of other components in a device.”

Victoria Woollaston, Daily Mail 

“Battery life is consistently listed as a major flaw of smartphones, smartwatches and other wearables.  But this problem could soon be solved thanks to technology that promises to extend battery life for ‘decades.’ Atmel has released its latest microcontrollers (MCUs) for a variety of gadgets that are so low power they can even harvest energy from a person’s body.”


“They use a third of the power of rival chips and tests have shown they are the lowest power microprocessor ever made. The microcontrollers run on the firm’s picoPower technology and Atmel’s Event System that makes different parts of the device work together to carry out tasks. By effectively ‘sharing’ energy, the whole device uses less power and, subsequently, less battery.”

Jamie Condliffe, Gizmodo

“As everything around us, from phones and fridges to bicycles and trash cans, begins to connect to the Internet, there’s an increasing desire for low-power chips. Like this one, which can last for over ten years on a single battery charge. It has some other clever tricks up its sleeve. Usually in a chip like this, sleep mode sees everything but the clock function shut down, meaning it has to wake every time connected devices need to communicate; this new Atmel chip has different sleep states, allowing connected devices to communicate with each other while the chip continues to use very little power.”

“Of course, the chips don’t pack huge amounts of grunt. In fact, at best you’re looking at a 42 MHz Cortex M0+ CPU core, 256 kilobytes of Flash memory, 32 kilobytes of static RAM, and 8 kb of separate low-power static RAM. Not enough to run a desktop OS, then, but plenty to run small programs, power hardware interfaces, read and record data from sensors, tweet and the like.”

JC Torres, SlashGear

“Batteries, already the Achilles heel of mobile devices, present an even bigger challenge for even smaller devices, like wearables and the budding Internet of Things industry. These latter devices are not things that you would, or should, associate with the frequent charging and battery replacement we are used to on smartphones. How do you balance performance and battery life? Atmel, a micro-controller manufacturer based in San Jose, may have the answer. Its new ultra-low power SAM L21 32-bit ARM-based MCU (micro controller unit) is advertised to last more than a decade before needing a recharge or replacement.”


“That kind of battery life will be critical for a certain class of devices that include sensors, wearable, and smart home appliances. The SAM L21 advertises a power draw of only 35 microamps per MHz when awake and an even smaller 200 nanoamps when asleep. In comparison, current low-power MCUs already eat up to 120 to 160 microamps per MHz. The difference it definitely substantial.”

Patrick Nelson, Network World

“The Internet of Things is about to reverse a lot of what we’ve wanted in a chip. Soon, we won’t need vast amounts of calculations per second — just how many instructions does it take for your fridge to send an order to your supermarket? Not that many when you compare it to something complicated that chip design has been working towards, like a Computer Aided Design drawing in 3D, for example.”

“Size is important. However, the real big issue, when it comes to a ubiquitous IoT where everything is connected, will be battery life. The reason is that we are not going to want to change the batteries within the base of a dozen bottles of water that we may have sitting around just to discover whether we’ve drank their contents or not. Even if your fridge orders fresh stock, it wouldn’t be worth it.”

“That battery has to last the life of the connected object in the IoT. And that could be 10 years away, possibly longer. Atmel reckons it has a solution. It says its new 32-bit ARM-based chips will last decades. Note the plural. Atmel says its new chips combine battery-saving low power with flash and SRAM that is big enough to run both the application and the IoT-needed wireless stacks.”

Shaun Nichols, The Register

“Being a Cortex-M0+-powered chip, the SAM L21 is not particularly powerful: it tops out at 48MHz, and runs ARM Thumb (and some Thumb-2) code. But the family does pack a few features like USB interfacing, op-amps and comparators, DMA with peripherals, a random number generator, and AES cryptography in hardware, plus other bits and pieces. The idea is for each chip to sleep, wake up when something happens, make a decision on whether or not it needs to alert the wider world, and then go back to sleep.


“Constantly being in contact with its base over wired or wireless networking will drain its batteries; activating external electronics for power-hungry IP communications should only be done if its sensors detect something significant. Like an explosion or a fire.”

Gordon Hunt, Silicon Republic

“Sensors and batteries – the two keys to unlocking the future of IoT. Can we make small enough sensors to garner and exchange the right data? Can we make small enough, powerful enough, batteries that don’t need recharging every few hours?These are the two questions posed for today’s inventors, and they are being answered every day. Now, Atmel’s latest creation may have brought significant IoT engagement closer to reality, with its new low-powered 32-bit SAM L controller able extend the battery life of small, low-powered intelligent devices by decades.”

“The result is a far more efficient, small controller that, if advanced upon in the right way, will open up a whole new swathe of devices for IoT innovation. It’s just a sample, prototype release so far, but once the right people get their hands on this it’s only a matter of time before it creeps into suites of low-powered devices.”

Rich Quinnell, EE Times

“This week TI surpassed its own earlier result by announcing the MSP-432 family based on the Cortex M4F. It achieved a ULPBench score of 167.4. While TI was briefing the media on this product, however, Atmel quietly published a ULPBench score of 185.8 for its SAM L21 MCU based on the Cortex M0+, a product announced last year that was scheduled to be released at about this time. It’s reasonable to expect that a formal announcement of the product’s score and availability will be made soon.”


Clive Maxfield, Embedded

“When it comes to applications including the Internet of Things (IoT), consumer, industrial, medical, and other battery-powered devices — e.g., fire alarms, healthcare, medical, wearable, and devices placed in rural, agriculture, offshore, and other remote areas — ultra-low-power consumption is the name of the game. MCU manufacturers are constantly competing with each other to offer the lowest power consumption possible. The latest ultra-low-power offering comes from the folks at Atmel, who have just announced their SMART SAM L21 — an ARM Cortex-M0+ based family of MCUs that boast power consumption down to 35µA/MHz in active mode and 200nA in sleep mode — which is said to ‘extend battery life from years to decades.’”

“The L21 goes much further than simply gating the clocks — it also gates the power, completely disconnecting the power rails from functions that are not currently in use. In the case of the smart peripherals, even when they are powered down, a small part of each peripheral keeps a ‘watchful eye’ on what’s happening in the outside world. If it sees something interesting, it can request clock and data services and — if the peripheral decides the situation justifies such an action — it can wake the main CPU… Also of interest is the CCL (custom configurable logic) block, which boasts four 3-input lookup tables (LUTs) that can implement a mix of combinatorial logic functions (AND, NAND, OR, NOR, XOR, XNOR, NOT) and sequential logic functions (gates D-type flip-flop, JK-type flip-flop, gated D-type latch, RS latch). These can be connected to the event system (including the peripherals), the interrupt system, and general-purpose input/outputs; also, they can be cascaded together. This makes it possible to implement sophisticated customized “wake-up” conditions for the various functional blocks.”

Interested learning more? You can head over to our initial blog post on the topic, download its accompanying white paper, as well as delve deeper into the MCU lineup here.

Flexible battery eyes next-gen wearables

Rice University researchers have created a flexible battery that could potentially power future generations of wearable devices. 

Developed by Rice chemist James Tour and his colleagues, the design comprises flexible material with nanoporous nickel-fluoride electrodes layered around a solid electrolyte.


The flexible power source delivers battery-like supercapacitor performance, combining the best qualities of a high-energy battery and a high-powered supercapacitor – without the lithium found in current commercial batteries.

According to Rice postdoctoral researcher Yang Yang, the electrochemical capacitor is about a hundredth of an inch thick, although it can be scaled up by increasing the size or adding layers. In terms of slimming down the battery, Tour believes standard manufacturing techniques will likely allow the battery to become even thinner. 

In tests, the students found their square-inch device held 76 percent of its capacity over 10,000 charge-discharge cycles and 1,000 bending cycles.

As Tour notes, his team set out to find a material that offered the flexible qualities of graphene, carbon nanotubes and conducting polymers – all while possessing significantly higher electrical storage capacity typically found in inorganic metal compounds. Unfortunately, inorganic compounds have, at until recently, lacked real flexibility.

“This is not easy to do, because materials with such high capacity are usually brittle,” he said.


“And we’ve had really good, flexible carbon storage systems in the past, but carbon as a material has never hit the theoretical value that can be found in inorganic systems, and nickel fluoride in particular.”

Yang expressed similar sentiments.

“Compared with a lithium-ion device, the structure is quite simple and safe. It behaves like a battery but the structure is that of a supercapacitor,” he explained. “If we use it as a supercapacitor, we can charge quickly at a high current rate and discharge it in a very short time. But for other applications, we find we can set it up to charge more slowly and to discharge slowly like a battery.”

To create the battery/supercapacitor, Tour’s team deposited a nickel layer on a backing, subsequently etching it to create 5-nanometer pores within the 900-nanometer-thick nickel fluoride layer (facilitating a high surface area for storage).


Once the researchers removed the backing, they sandwiched the electrodes around an electrolyte of potassium hydroxide in polyvinyl alcohol. Testing found no degradation of the pore structure even after 10,000 charge/recharge cycles. Similarly, the scientists confirmed no significant degradation to the electrode-electrolyte interface.

“The numbers are exceedingly high in the power that it can deliver and it’s a very simple method to make high-powered systems,” Tour added. “We’re already talking with companies interested in commercializing this.”

Batteries with potential 40-year life

I just saw an ad for a Tadiran battery that claims a 40-year life. This is for a primary battery, not a rechargeable. That is based on the 1% per year self-discharge rate. So the math is pretty basic— 40 years at 1% per year and that is more than 50% charge remaining to do your bidding. Now the ad, being marketing and all, does not say if its 1% of rated capacity per year, or 1% of remaining capacity per year. You should have plenty of charge left if you figure your power budget with a factor of two over rating to allow for that self-discharge.


Tadiran’s previous lifetime champ was also (Li/SOCl2 ) cells. They would claim 15-year lifespans for those. SAFT makes lithium thionyl chloride cells too. I assume Tadiran have made further improvements to get to such a low self-discharge rate for this line, which they call lithium inorganic. But I note the Tadiran ad has the words “…in certain applications.”  You see, they can’t tell where or how you use the batteries. If you leave flux all over the board so that there are leakage paths, you won’t get the 40 year life. If you run them at hot or cold temperatures, you won’t get the 40 year life. If you take out the current in high pulses instead of a gentle steady current, you won’t get the 40-year life. It is not Tadiran’s fault. They have to give you the optimum spec— that is for a battery with no leakage paths other than its own case. And measured in a comfortable temperature in a dry environment.

When I was at EDN I wrote about the 15-year batteries. An alert reader notified me of a scandal in Houston Texas since the gas meters needed new batteries much sooner than expected. Once again, it was not the battery maker’s fault. Houston Texas is extremely humid, almost tropical. The batteries in the meters were exposed to this humidly and high temperature and their life was much shorter.

I designed the power system for an automotive diagnostic tool when I consulted at HP. I thought I had all the battery quiescent currents figured out in a neat little spreadsheet. Then I prototyped the design. The leakage current was much higher than my spreadsheet showed. Turns out that battery voltage was flowing through the body diode of a back-to-back FET and then into a gate pull-down resistor. I used a 1meg resistor, but 12 volts into 1 MΩ resistor is still 12μA. That is way more than the 200nA memory retention current of an AVR XMEGA in shutdown, so don’t let some power supply leakage path screw up your battery life calculations like I did.

In 2007 I did a follow-on post about smart meter batteries. The broken first link in it is the EDN article I linked above. So just remember, it is your job, not Tadiran’s, to insure that the battery life is what you expect in a smart meter. Tadiran can give you the battery, and Atmel can give you the MCU and smart meter ICs, but you have to verify the leakage and current consumption in your exact application, running your exact code, with your exact manufacturing methods. My buddy Eric Schlaepfer, now at Google, was over at Maxim when some customer contacted him and called Maxim liars since the customer was getting much greater power consumption on one of Maxim’s micro-amp supervisor chips. It turns out the customer was letting the PCB get contaminated with sweaty conductive fingerprints in assembly. The leakage current through those fingerprints on the PCB was passing way more current than the integrated circuit.

So brush up on the Keithley low-level measurement handbook (pdf), so you can measure those nanoamperes. And be sure to test your system in temperature and humidity chambers that simulate the real world. And then take measurements in the field to validate all your assumptions. Then and only then will you get 40-year battery life in your products.

An interview with Steve Laub: President and CEO of Atmel

On May 27th, Steve Laub, President and CEO of Atmel, was interviewed by the Wall Street Transcript. The CEO discussed a number of subjects with the prestigious publication, including the recent acquisition of IDT’s smart metering product line, the purchase of Ozmo Devices and the Internet of Things (IoT).


“Today, it’s estimated that there are nearly 10 billion devices in the world connected to the Internet, and this is expected to triple to nearly 30 billion devices by 2020,” Mr. Laub explained. “The ‘Internet of things’ represents perhaps the greatest potential growth market for semiconductors over the next several years.”

The CEO also noted that Atmel remained focused on designing the absolute lowest-power products, particularly in microcontrollers.

“As the world becomes more mobile, more devices are becoming portable and battery-powered. Therefore, ultra-low-power consumption is important for success, and we bring out the lowest power products in the marketplace,” said Mr. Laub.

“In addition, we are willing to move quickly. For example, a key reason we have been able to get into the market for touch sensing, the IoT and the smart metering markets, is because we are willing to act and make decisions quickly, such as to make the necessary acquisitions when required to enhance our technology.”

The full Wall Street Transcript interview with Atmel President and CEO Steve Laub can be read here in .PDF format.