Sunnyvale, Calif.--June 19, 1997--Philips Semiconductors Inc. (Sunnyvale, Calif.) announced two new high-speed triple 8-bit ADCs (Analog-to-Digital Converters) enabling LCD projectors and other video equipment to obtain the maximum dynamic range from any video signal input.
The TDA8752H/8 and TDA8752H/6, combined with SVGA screen resolutions and 16-million color displays, allow the latest generation of LCD projectors to bring multimedia presentations to life.
With maximum sample rates of 80 MHz (TDA8752H/8) and 60 MHz (TDA8752H/6), both Philips ADCs feature independently programmable RGB input channels with programmable gain control and black-level clamping on each input. These features allow any video signal with a black-level offset as high as plus or minus 0.25V and peak-to-peak amplitude between 0.4V and 1.2V to be clamped and scaled to the 1V full-scale input of the ADCs.
An on-chip PLL circuit allows sampling to be phase-locked to video line frequencies between 15 kHz and 280 kHz, giving LCD projectors true multiscan capabilities. Minimal PLL jitter ensures faithful reproduction of high-resolution PC graphic displays, and the sample rate can also be controlled directly from an external clock source. For even higher screen resolutions, an antiphase clock output allows a second TDA8752H to be slaved to the first in order to achieve sample rates as high as 160 MHz.
A major problem in LCD projectors has been the gain drift in AGC circuitry due to the high equipment temperatures that result from power dissipation in the projection lamp. The TDA8752H overcomes this problem by featuring a unique autocalibration facility that calibrates the gain of its three AGC amplifiers at the beginning of each video line. This eliminates the need to re-adjust picture quality as the projector warms up.
The TDA8752H is fully programmable via a serial control interface that operates in industry-standard I2C-bus or three-wire serial interface modes. It outputs 8-bit binary coded RGB data via TTL-compatible three-state parallel output ports. Operating from a 5-V supply, its total power dissipation is typically less than 1 W, but it also features a power-off mode that saves power consumption in battery-powered portable equipment. In addition to its targeted application in LCD projectors, the TDA8752H is suitable for use in any equipment where high-speed, high-quality digitization of RGB video signals is required.
Samples of the TDA8752H, packaged in a 100-pin QFP, are available now. Volume shipments will begin in the third quarter of 1997.
(800) 447-1500 ext. 1393
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