Samsung Debuts Trio of High-End True Color RAMDACs

Fully Compatible Devices Offer Direct Support for Innovative Window RAM

SAN JOSE, Calif., July XX, 1994 -- Samsung Semiconductor made significant strides in its efforts to overtake the competition today, introducing a trio of true color RAMDACs that offer computer graphics card makers the best of both worlds. Samsung's new true color RAMDACs support Samsung's revolutionary Window RAM while also offering drop-in replacement for similar devices used in existing high-end PC graphics cards.

Samsung's KDA0484, 485 and 486 offer direct connection to Samsung's price/performance-leading Window RAM without the need for additional external circuitry, providing the most complete solution for putting larger, faster, more colorful displays on every user's desktop at affordable prices. The trio of RAMDACs also support conventional VRAM, and the KDA0484 is fully compatible with the Brooktree Bt484 and AT&T ATT20C484 RAMDACs, while the KDA0485 is fully compatible with the Brooktree Bt485 and AT&T ATT20C485 RAMDACs. All three Samsung RAMDACs are pin-compatible, as well.

"Six months ago, Samsung introduced its first true color RAMDAC, and now Samsung is poised to take the lead in the RAMDAC market," said George Brecht, Samsung's chipset marketing manager. "Today, we are in a much better position to blend other multimedia technologies to create innovative products to serve tomorrow's needs."

According to market researchers at Instat, the number of true color graphics boards produced in the U.S. in 1994 will reach 7.2 million units, and Samsung estimates half of them will use RAM DACs compatible with the KDA0491. Worldwide, Instat estimates a total of 11.9 million units will be produced in 1994.

Improved Performance

Samsung's true color RAMDACs significantly improve the performance of Windows applications by enabling multiple applications to simultaneously use 16.8 million colors. Each application's window has access to the colors it needs. Without true color capability, applications often have to contend for the more limited 256 colors offered by other graphics solutions, and may not be able to display the desired colors.

True color also helps eliminate aliasing, the jagged edges most noticeable on diagonal lines, by providing each pixel with a full range of colors. With true color, each pixel in a diagonal line can be color blended with the surrounding pixels to soften the line's edges and make it appear smoother.

Designed and manufactured using Samsung's proprietary single-poly, double-metal, 0.8-micron CMOS technology, the KDA0484/485/486 are specifically designed for high-performance applications. They feature four byte-wide pixel input ports and a separate 8-bit VGA port, and support VGA in a true color window. The RAMDACs' three 256 by 8 color look-up tables and triple 8-bit digital-to-analog converters are capable of displaying 16.8 million colors simultaneously. The KDA0484 features a 75- or 85-MHz pixel clock, and can display graphics with resolutions up to ______ by ______ pixels. The KDA0485/486 offers a 110- or 135-MHz pixel clock, and can display graphics with resolutions up to _________ by _________. All devices offer snow-free operation. The KDA0486 adds two features to the 485: a 24-bit packed pixel mode with 4:3 multiplexing for improved throughput and support for a 16-bit pixel bus.

The KDA0484/485/486 provide a standard microprocessor interface for complete microprocessor control over the RAMDACs' internal registers and color and overlay palettes. The auto-incrementing address register enables continuous color look-up RAM access after being initialized with a starting address.

The KDA0484/485/486 operate with a single +5-volt power supply, and typically draw 260 to 300 mA (75 to 135 MHz) while operating. A power-down mode reduces power consumption to 5 mA when the analog outputs are not being used. Useful in portable computers that need the option of supporting an external analog monitor, the power-down mode automatically disables the external voltage reference, but retains RAM data and permits the reading and writing of data as long as the pixel clock is running. On-chip monitor sense comparators enable the automatic detection of color and monochrome monitors (or no monitor at all), and a unique internal, non-trimming bandgap voltage reference provides more reliable and stable operation.

The segmented architecture of the internal DACs reduces the switching transient response, guaranteeing low glitch impulse and monotonicity. The DAC accuracy (grey scale error) is specified at a maximum of ±5% of grey scale, and linearity is ±1 LSB for both integral and differential errors.

Pricing and Availability

The KDA0484/485/486 RAMDACs are available now in sample quantities. Prices for the KDA0484 are $x.xx (75 MHz) and $y.yy (85 MHz) each, the KDA0485 costs $x.xx (110 MHz) and $y.yy (135 MHz) each and the KDA0486 costs $x.xx (110 MHz) and $y.yy (135 MHz) each, quantity 1000. All versions are packaged in an 84-pin PLCC.

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