Global Sources
EE Times-Asia
Stay in touch with EE Times Asia
EE Times-Asia > Amplifiers/Converters

Leadis exec discusses class G technology

Posted: 20 Nov 2007 ?? ?Print Version ?Bookmark and Share

Keywords:class G? amplifier technology? Leadis executive?

Hauer: The technology is too interesting and potentially lucrative not to take class-G amplifier into the higher-power space.

Leadis Technology Inc. in August announced a family of audio codecs using a proprietary Gmax amplifier technology that the company claims dramatically increases power efficiency and maintains best-in-class SNR. The LDS9350 and LDS9302L were scheduled to ship in volume this quarter.

Leadis Technology's Jim Hauer, senior director for new business development, recently spoke with Vivek Nanda, EE Times-India editor, about the company's businesses and product road map.

EE Times-India: Tell me about Leadis' businesses.
The company was established 2000 to offer display drivers. So LCD drivers is the primary business and it is very successful in many consumer markets. But you know the price pressures, integration and all those different things going on. Since they were successful, our products were a target for competing devices and extreme price pressure really had a strong impact on the profitability.

Some time in 2006, therefore, the senior management and the board of directors developed a strategy to expand product offerings, branch out into other areas. The primary application for LCD drivers was mobile phones. So they expanded the concept to portable products.

As an analog and mixed-signal company, we have developed LED driver technology and the company is working on capacitive touch screen technology. Our audio division was an established company called Mondowave Inc. that Leadis acquired. So that gives you our tag line: Sight, Sound and Touch.

Do you see any price pressures from Asia?
It's probably pressure from the U.S. and international companies. We're viewed a little bit as a start-up in audio, though we're a public company in America. The company shipped 100 million units last year. With the 100 million units the revenue was smaller than what it was when we shipped 60 million units two years before that.

When are you planning to introduce the touch-screen products?
They will be introduced at the end of this year so it's a bit early to talk about these products. But we have a team developing these products and talking to partners and customers and I believe we are targeted to release the first of these products by the end of Q4 this year.

How do you see 2007 shaping out? Do you see a slow down?
Not particularly in our markets, no. Mobile phone business keeps growing. Even some of the other markets we target!MP3!what's interesting there perhaps is that some of the lower priced MP3 players, their business will get affected as MP3 players get built into cellphones. So the consumer will buy one device.

That's why we are targeting our audio development on performance, power consumption and feature set. As a company we are in a transition period for starting up these new businesses. The actual revenue contributed by these new product lines will just be starting this year.

Please describe your audio product offerings.
The audio business unit has two fundamental product targets!high-efficiency amplifiers and audio codecs. The high-efficiency amplifiers apply to the codecs as well.

In the codecs, we are focusing on low power consumption, some higher integration and power management. Size reduction, increased battery life and cutting the BOM cost are critical for portable devices.

In the high-efficiency amplifiers, it's an improvement on what's known as class G. Class AB has traditionally been used and is known for excellent audio quality, low component count, low EMI but high power dissipation.

The audio people try to use class D in space-constrained applications like LCD TVs and personal computers.

Class D has extremely good power efficiency and relatively good audio quality now, though it has a "harshness" to it. Also with class D, the better the audio quality, the higher is the cost due to the component count!EMI has always been an issue.

Class G, on the other hand, brings together the best of AB and D!there's no EMI because there's no switching going on and so there's low component count because you don't need all that filtering. It's a high-efficiency analog amplifier that uses multiple voltage rails. It switches to the appropriate voltage as required by the output of the device. So you never have a situation where it's using the full supply voltage for a minimal supply requirement.

Our first generation audio products include a stereo codec, with an analog input, digital connection, headphone and line out. So far the concept is well known in the industry. The significant breakthroughs however include a patented class G implementation called Gmax and an integrated DC-DC converter. What this allows is a single-supply operation. We can generate digital supplies and it also does the control on the multiple voltages.

What's your product road map?
The first of the products released between September and October will really contribute to revenue in the designs that come out next year. It's a low-power codec with an integrated FM transmitter. The original application conceived was an MP3 player that plays through your car and home stereo players.

In Taiwan, for instance, there's a strong demand for our stand-alone FM transmitter as well because Taiwan is a strong developer of personal navigation devices (PND). There are a couple of dominant suppliers... 50-odd components and lots of tuning. The Leadis stand-alone part requires just five external components and handles all worldwide FM bands.

For the next-generation of products, we are focusing on D/A and A/D conversion performance, power consumption and system integration, including more I/O.

In future, we will also apply class G to higher power. The technology is too interesting and potentially lucrative not to take class-G amplifier into the higher power space. Our first product will come out in 2008 and will address multichannel and specifically car stereo and LCD TVs.

In addition to Gmax in the ground-centred standalone headphone amplifier, there will be some power supply management that will give it an extended voltage range, which would give the system developer the choice to either have a direct voltage or connect directly with the lithium-ion battery.

- Vivek Nanda
EE Times-India

Article Comments - Leadis exec discusses class G techno...
*? You can enter [0] more charecters.
*Verify code:


Visit Asia Webinars to learn about the latest in technology and get practical design tips.

Back to Top