NATIONAL'S NINE-LEAD TRIPLE-CHANNEL FAMILY OF MONOLITHIC CRT DRIVERS ADVANCE PRICE/PERFORMANCE LEAD OVER OTHER DESIGNS

New Family Offers Cost Savings, Lower Power For 14- to 17-Inch Displays, Especially when Teamed with National's High-Performance Video Preamps

August 9, 1999 -- National Semiconductor Corp®. today announced a new family of pin-to-pin compatible monolithic triple CRT drivers that offer price and performance advantages over other design solutions, including discrete and hybrid approaches. The four cost-effective LM243x drivers, housed in space-saving nine-lead packages, are targeted for 14-, 15- and 17-inch color monitors with resolutions up to 1024x768 (XGA) and 1280x1024 (SXGA), respectively.

"National offers the only monolithic CRT drivers on the market today. These new LM243x products are designed to increase our advantage by offering the price and space savings plus the performance customers need in cost-sensitive applications," said Muthanna Salman, Displays marketing manager at National. "For example, because of the reduced power dissipation, smaller heat sinks are required, which helps cut overall system cost," Salman said. "The LM243x packages, which reduce pin count from 11 to 9 leads, are half the size of their predecessors, resulting in space and system cost savings."

The LM2435 is a 5.5ns triple CRT driver designed for such applications as 1280x1024 monitors with up to a 75Hz refresh rate and pixel clock frequencies up to 135MHz. The LM2437 is a 7.5ns triple CRT driver designed for 1024x768 monitors with up to 85Hz refresh rates and pixel clock frequencies up to 100MHz. The LM2439 is a 9.5ns triple CRT driver designed for 1024x768 monitors with up to 70Hz refresh rates and pixel clock frequencies up to 75MHz. And the LM2438 is a 13.5ns triple CRT driver for 1024x768 displays and monitors with up to 60Hz refresh rates and pixel clock frequencies up to 60MHz. All four also are designed for monitors using video blanking.

Each monolithic high-voltage device contains three high-input impedance, wide-band amplifiers that drive the RGB cathodes in a CRT. Each channel has its gain internally set to -14 and can drive CRT capacitive loads, as well as resistive loads present in other applications, limited only by the package's power dissipation.

"This new driver family is well matched with National's high-performance LM12xx family of video preamplifiers," Salman said. "Together, they provide customers with a video channel chipset that has leading price and performance attributes." The four drivers share such specifications as a 0V to 5V input stage, stable 0pF to 20pF capacitive loads and inductive networks. Because they conveniently use the same TO-220 staggered lead package style and a standard LM243x family pinout, the four drivers offer CRT designers a consistent PCB design that significantly improves time to market.

They operate from power supplies ranging from +60 to +85V. The cascode output stage is capable of driving 8pF, 40Vp-p swing at a maximum output voltage of 68Vdc.

Pricing and Availability
Available now, the CRT drivers are priced (1000 unit quantities): LM2435, $3.56; LM2437, $2.20; LM2439, $1.45; and the LM2438. $1.30 each.

About National Semiconductor
National Semiconductor provides system-on-a-chip solutions for the information age. Combining real-world analog and state-of the-art digital technology, the company's chips lead many sectors of the personal computer, communications, and consumer markets. With headquarters in Santa Clara, California, National has annual sales of $2 billion and 11,500 employees worldwide. Additional company and product information is available on the World Wide Web at www.national.com.