Balu Balakrishnan is president and CEO of Power Integrations Inc. (PI) of San Jose, Calif. After joining PI from National Semiconductor in 1989, he served in a variety of technical and executive roles before becoming CEO in 2002. He is chief inventor of the company’s TOPSwitch and TinySwitch technologies, and holds more than 85 U.S. patents. Power Integrations is the leading supplier of high-voltage ICs for power conversion, serving the ac-dc and high-voltage dc-dc power-supply markets.
PI has staked out a leadership position in power conversion. How did you arrive there?
It’s been a matter of understanding our strengths and focusing on developing and leveraging them. Our fundamental competitive advantage comes from our high-voltage silicon technology, and we’ve built our business around that. We focus exclusively on the power-supply market, where high voltage is essential, and we’ve developed a wealth of intellectual property in circuit and system design for power supplies. None of our competitors can match that.
What are the unique challenges you face in serving the power-supply market?
Consumers are generally indifferent to power supplies, so OEMs don’t consider them in their product’s value proposition. As a result, the industry has been slow to adopt new technology, and many ac-dc power supplies still use outdated technologies like discretes and linear transformers.
Is there anything that could cause the pace of change to accelerate?
Absolutely. Energy efficiency is becoming an extremely important driver. It’s been a factor in our business for a while, but we’re still in the first chapter of the story. Efficiency standards are only going to get tighter, and they will apply to an ever-broader range of products. And as consumers become more aware of the benefits of efficiency, OEMs will increasingly see efficiency as a differentiating factor. These trends are going to accelerate the shift to IC-based power supplies.
When did energy efficiency enter the equation for PI?
Our first commercial product, TOPSwitch, was inherently more efficient than discretes, but energy efficiency wasn’t a major focus for us at the outset. Then in 1997, I first heard about standby power, the electricity wasted when products are plugged in but not being used. I realized that we might be able to help solve the problem.
And that solution was EcoSmart?
That’s right. At the time, we were developing our TinySwitch product line, which uses on/off control instead of pulse width modulation (PWM). We realized that on/off control presented a perfect solution for the standby problem. As load diminishes, you simply eliminate cycles. The result is high efficiency even at very light loads, whereas the efficiency of PWM starts to diminish as the load decreases. If there’s no load at all, such as when a cellphone charger is plugged in but detached from the phone, you only use a few milliwatts—just enough to power the IC. Compared to a linear transformer, which can easily use a watt or more of no-load power, the energy savings are dramatic.
You’re on something of a personal crusade to get rid of linear transformers. Some people call them “energy vampires” because of their inefficiency. How has that effort progressed?
Frankly, our initial efforts were somewhat frustrating. In 2002 we came out with LinkSwitch (short for Linear Killer Switch), but it turned out that having a cost-equivalent solution wasn’t enough. There was simply too much inertia keeping the linears in place. That’s finally changing. Tough, mandatory efficiency standards on external power supplies are about to go into effect in California and other states, as well as Australia. And raw materials like copper and iron continue to get more expensive. As a result, we’ve seen a tremendous increase in the rate of linear replacement in the past year. I think that we’ll soon see linear transformers go the way of vacuum tubes.
Up to now, most efficiency standards have focused on standby, but active-mode efficiency is now increasingly important. The California standards, for example, require measurement at zero, 25%, 50%, 75% and 100% loads, so high efficiency across a range of loads is a critical design consideration, and we can deliver that. Our new PeakSwitch products, for example, deliver 80 W of peak power at 80% efficiency, while only using 80 MW at no-load. You can’t achieve that kind of performance without integration.