With a plethora of battery-draining apps being added to wireless handsets, chip-makers are devising increasingly sophisticated power management solutions.

The natural progression of the mobile handset market dictates that devices will get smaller even as more apps and capabilities are added. But 3G — and someday 4G — applications demand a lot of battery juice, and the now-standard lithium ion handset batteries aren't keeping up with the devices they power. Organizers, downloadable ringtones, MP3s and streaming video all make our mobile lives more entertaining, but what is powering all of this?

Enter hand-held mobile device power management solutions, an increasingly important aspect of the mobile phone. Basically, power management chipset components manage the battery's charge to optimize battery performance and longevity, preserving talk and standby times even while adding more functionality to a mobile handset. The concept has been around since the birth of the mobile phone, but it has become increasingly more important over the past few years as mobile devices have become more complex.

The mobile phone's shift from analog to digital technology helped save battery life, but software is still necessary to manage the charge. Power management chips integrate the actual functions of a device with the power management of those functions to make all the parts of a phone work together in the most efficient way while using the least amount of battery power.

“In the last year or so, there's been a real acceleration and a real sophistication [in power management solutions],” said Chris Ambarian, senior analyst for power management for iSuppli Corp. “It's never been so sexy to be in power as it is right now because everything is bumping into the same problem: energy efficiency.”

There are two main reasons why power management has become so important over the past few years. The first is that consumers are becoming accustomed to steadily increasing talk and standby times, and they're not willing to compromise battery longevity for enhanced multimedia features. Brian Carlson, core technology marketing manager of cellular systems business for Texas Instruments, estimates current talk and standby times are as much as 300 hours of standby and 300 minutes of active time, and they're not going down any time soon (see figure).

“Talk and standby times can be increased incrementally and are still going up, which is amazing,” Carlson said. He doesn't expect talk and standby times for wireless handsets to increase by a lot over the next few years because of current lithium ion battery limitations. “Most of the effort right now is just trying to keep what we have today, but there will be incremental increases,” he said.

Another consideration for battery longevity and power is the form factor or size of the phone. The introduction of Motorola's reed-thin Razr phone has sparked a revolution among consumers who are constantly seeking ever-thinner handsets. Smaller handsets require smaller batteries, which often are less powerful, so the phone has more to accomplish on less power.

“The form factor on the phones is decreasing rapidly, and demand on the battery is going up so the challenge falls on our shoulder to make sure that the thinner the battery gets, we still can deliver all the demand that this is putting on us,” said Al Zahedi, Qualcomm's director of product management for CDMA technologies.

There seem to be more similarities than differences between power management chips. Some power management solution manufacturers have built chipsets to integrate with their software chip offerings. One example is TI's SmartReflex power and performance technology, which integrates with the company's OMAP multimedia processor platform. The advantage to this type of approach is that it is built in a holistic way so that the processor and the power management software can work together to maximize power longevity while increasing performance output. The SmartReflex combines adaptive silicon, circuit design and software, which TI is applying to devices at the 65 nanometer level.

In the past, power management of handsets was much simpler — they had either a high-performance mode or were shut down, Carlson said. “Now you have to dynamically change it. Every second you're changing the power so you have the right power for the right performance,” he said. “It's a very dynamic process, whereas in the past it was not that aggressive. You have to do this to be competitive today.”

Qualcomm's series of power management solutions integrates applications software with power management function. The solution is designed to be used with the company's Mobile Station Modem chipsets, which offer solutions for value-priced, mainstream and high-end phone models.

“Our chip is designed with our baseband part in mind, our RF parts in mind,” Zahedi said. “Every chip has to talk to each other, and every chip has to know the status of the other chip. We're providing software packages, we're providing hardware, so it's a one-stop shop, basically.”

Managing the power dissipation in the form of controlling the heat output is important as well, said Edward Yeow, operations manager for power management products for Freescale Semiconductor. Whenever a battery is transmitting power, it is transmitting some energy, which gets lost in the process and represents itself as heat dissipation — and that can become uncomfortable for the user if there's too much heat lost.

Handset chipset designers are working to constantly bring down the amount of power the different parts of a device need to run, while also trying to more efficiently manage the power they do consume. One method they use to do that is voltage scaling, which is the intelligent use of DC-to-DC converters to give them whatever voltage they need, whenever they need it and no more, iSuppli's Ambarian said. They have several process technologies to minimize the amount of power that they draw.

“At the end of the day, the requirements in the portable arena are basically battery life, density — how small is the component — availability and cost,” Yeow said. Freescale's newest power management product offering, the MC13783, can be used as an individual system or integrated with one of the company's total platform solutions.

As devices evolve, power management systems will have to evolve as well, Ambarian said. In order to compete in the space, chip-makers will have to make it easier for handset designers to use their products. Part of what will make a power management scheme work is that it is modular and repeatable, and it doesn't require a custom rebuild every time it is used in a different handset, he said. If it meets these basic requirements, the design can be used for multiple handsets without losing efficiency.

“They need to take the experience to the next level for the design engineer. It still needs to be a little simpler; the user interface needs to be a little cleaner and straightforward,” Ambarian said. “Right now, you have to be pretty sophisticated on the software side to take full advantage of all this … but more could happen, more would happen, if it was much simpler.”