Sponsored by National Semiconductor Corp.
Building More Competitive Displays: Better Chips + Better Chip Production = Better Displays
By Mitch Irsfeld

Samsung Electronics became the LCD market-share leader after it partnered with National Semiconductor. Here's how Samsung's Sang-Soo Kim and National delivered improved performance and lowered costs.

While declining prices for thin-film transistor (TFT) displays have expanded the market for flat panels on desktops, in automobiles and, of course, on laptop computers, heightened consumer expectations for color, higher resolutions and less weight continue to bedevil display manufacturers and their semiconductor suppliers.

In no other sector of the electronics industry is pressure greater to lower costs while increasing functionality and reducing time to market. Working with their suppliers, manufacturers must build more competitive displays--especially flat-panel displays--for notebooks and desktops as well as for smaller portable devices like PDAs and cell phones. The most effective way to accomplish this goal and drive profits in this competitive arena: leading-edge component technology.

Samsung Electronics has become a leader in TFT displays largely because of the close partnership between its Seoul, South Korea-based design team and National Semiconductor. The relationship has resulted in several industry firsts. Teaming with National to develop integrated chipsets, Samsung introduced industry standards like LVDS (low-voltage differential signaling) and RSDS (reduced swing differential signal) interconnect technology. RSDS improves performance while substantially reducing power consumption, weight and costs. LVDS uses true differential transmission to reduce EMI (electromagnetic interference) while maintaining a high throughput of 5.38 gigabits per second.

"These technologies represent the standard in the industry, and Samsung and National Semiconductor both lead this industry," says Sang-Soo Kim, Ph.D., Samsung vice president, R&D team, AMLCD division, Device Solution Network. "Samsung was the first company to introduce these technologies to the market. These are single chip solutions and they are going into all our TFT panels. And this kind of integration will continue for the next generation of TFT-LCD driver technologies."

Samsung Semiconductor now manufactures the chips, under license from National. The main advantage of LVDS and RSDS interconnect technologies in the integrated chipsets, according to Kim, is a drastic reduction in the number of components and the size of the printed circuit boards.

"Our timing controller has a built-in LVDS receiver and RSDS transmitting unit," says Kim. "We can improve our production abilities with the integration of discrete components on a single chip and make our chips with better performance than our competitors. The integration allowed us to reduce the size of the PCB by half and cut the number of components in half. And we reduced the number of layers to four, rather than six or eight. That is one of the keys to making our panels thinner, lighter and EMI free. This allows us to include other components on the PCBs and provide cost-effective solutions for our television and monitor makers. With our advanced technology, we can reduce our cost substantially over our competitors."

Diversifying Fabs

Low-temperature, poly-silicon TFT displays provide the best definition available on the market. The images are precise, even on a small screen, and the number of driver circuits used is far less than other types of displays.

TFT-LCD panels have made dramatic inroads as notebook and PC monitor displays. But Samsung and other large display manufacturers already are diversifying their fabs to use the newer technology across other product areas, including televisions, PDAs and cell phones. Samsung is expanding aggressively into midsize and small panels and focusing on the LCD-TV and mobile-phone segments.

How will future improvements in display technology impact users? Tune in to hear the insights of Mitchell Abbey, marketing director for National's displays division.

 

SHATTERING GLASS: The street price of various sizes of notebook and desktop flat-panel displays has declined significantly in recent years; the benchmark 15-inch display dropped almost 50 percent in the past 12 months. Prices for larger displays will continue to crumble through the next few years. ($ per unit actual and forecast) Source: DisplaySearch

Another good reason to diversify is the crumbling price of displays. Since early 2000, the average street price of displays has fallen by 50 percent or more (see chart, "Shattering Glass"). Furthermore, the notebook market is not nearly as fast-growing as it was. Its compound growth rate now is projected to be about 17 to 20 percent, whereas the LCD monitor market is projected to grow through 2006 at a compound growth rate of about 37 to 40 percent.

Despite an overall slowdown for monitor sales in the United States last year, sales of flat-panel displays doubled, according to market watcher iSuppli/Stanford Resources. Lower cost and additional features are attracting their use in automobiles as well as other devices (see chart, "Glowing FPD Outlook"). Sales growth for TFT-LCD monitors is expected to keep that pace for the next several years as consumers and business users warm up to the smaller footprint, reduced power consumption, higher pixel densities, wider viewing angles and flexible positioning of these devices.

Component Integration

Many of the technical advances are a direct result of component integration, and a key role for National Semiconductor is deciding what to integrate. "Right now, we've been looking at it from an interconnect standpoint and what goes through that interconnect," says Mitchell Abbey, marketing director for National's displays division.

"On a notebook, you have the signals coming from the graphics controller on the host side, and it goes across the LVDS transmitter to the LVDS receiver, to a timing controller, to the column drivers."

Hear Mitchell Abbey, marketing director for National's displays division, explain why laptops will be among the first products to see major improvements, courtesy of the latest screens.

With monitors, however, it's more complex, because the host potentially will demand more interconnects--everything from traditional RGB to DVI or TMDS, and now TV, each with different resolution and speed requirements.

GLOWING FPD OUTLOOK: Use of flat-panel displays in a wide variety of sizes will continue to soar. (millions of square inches of display surface, by end-use segment) Source: iSuppli/Stanford Resources

"Two years ago, everything was discrete," says Abbey. "Now, all our products are moving toward integration. We have one chip that is on our host side for the notebook, our integrated scalar and LVDS transmitter. On the display side, we have integrated LVDS receivers and timing controllers. And they are now pulling the timing controller and integrating that into what they call the smart panel. At the same time, you are starting to see op amps and regulators being integrated, and you've got audio coming on, so there will continue to be 'trash compacting' of the chips as you move forward."

New Applications

With integration comes new applications, and Samsung and other display manufacturers have big plans for TFT-LCDs beyond notebook and desktop monitors.

In the handheld arena, cell-phone applications represent the greatest opportunity. "People want to upload and download data and video from the Internet," says Abbey. "Eventually they'll want to have face-to-face conversations on their handsets. So they'll want the higher bandwidth and better color quality, but they don't want to sacrifice battery life to get it. And they aren't necessarily willing to pay very much more for it."

Will your eyeball be your next computer-interface device? Mitchell Abbey, marketing director for National's displays division, thinks that might very well happen. Tune in to hear his take.

"We're starting to see a definite interest in color and higher resolutions in both PDAs and cell phones," says David E. Mently, senior vice president of iSuppli/ Stanford Resources. "But we still need some changes in the displays--more pixels, better color, even some fancier graphics processors and accelerators inside the units to manipulate the images."

THE ROAD TO 40-INCH MONITORS: Lower cost through increased integration, along with higher performance, have been the twin pillars of National Semiconductor's development of display electronics for more than a decade. Among the key milestones are the introduction of low-voltage differential signaling (LVDS), which reduces EMI and improves throughput, and reduced swing differential signaling (RSDS), which improves performance while simultaneously reducing power consumption. Together, they enable total differential interconnect, which eliminates the need for separate transistor-transistor logic (TTL) as the interconnect. Source: National Semiconductor

Samsung is in mass production with 1.8-inch TFT-LCDs for this emerging market using the same technology found in its monitor and notebook display panels. And two-inch TFT-LCDs are in development. The company also is aggressively ramping up for strong LCD-TV demand.

"We are expanding our business to the small and medium size, and to LCD-TV," says Kim. "There is a huge demand on color cellular phones. We are the number-one supplier in LCD monitor and notebook displays now, and with LCD-TV, we will be the number-one supplier in two years."

In the notebook market, color resolutions and panel sizes continue to increase, forcing display manufacturers to continually achieve faster speeds while decreasing the power requirements for products that grow thinner and lighter each year.

Looking Ahead

State-of-the-art, 1600x1200 UXGA panels haven't made strong inroads yet, and some experts expect their adoption to be slow. For one thing, few mainstream applications demand such pixel densities. And for typical PC applications, the Windows operating system does not elegantly handle increases in display resolution.

"Video and enhanced video will always be the driver for TV displays, but that doesn't need ultra-high resolution," says Mently of iSuppli/Stanford Resources. "And for most PC applications, there is very little incentive to overload your pixels. Things like viewing angle and contrast ratio become more important to consumers, along with thinness and weight when it comes to handheld devices and notebooks."

But National's Abbey sees the demand for UXGA coming. "When I went to my OEM customers a year ago and asked, 'Will you put UXGA on a notebook?' the answer was, 'are you nuts?' But guess what, they are in production today. XGA is still the largest volume, but the projections are, within two years, it will be 1600x1200 resolution."

If that happens, display makers will be looking to get their speeds up from XGA at 65 MHz to UXGA at 160 MHz. In addition, they'll want advanced technologies that lower the EMI and enable them to continue making their displays thinner and lighter.

"That's the value of National Semiconductor," says Abbey. "When you add in our manufacturing clout and flexibility, it really allows them to reduce their costs and time to market."