Fairchild Semiconductor's FMS6407 is the first video driver to integrate circuitry for high-definition (HD), progressive scan, standard-definition (SD), and bypass filters into a single chip. Since this type of integration is the name of the game in integrated circuits, when something is done for the first time you have to ask, "Why now?" In the case of the FMS6407, the answer is process technology.
"The process that we have internally is much more stable and predictable, plus we have better simulation tools in order to predict what is going to come out—effectively the silicon matches the simulation," says Jeremy Tole, Fairchild's technical marketing manager for video products.
Knowing what to integrate is another issue. Integration in the FMS6407 includes a triple 6th order, active filter with selectable 30 MHz, 15 MHz, or 8 MHz cutoff frequencies that can be bypassed so that the bandwidth is limited only by the output amplifiers. The amplifiers have 0.6 percent differential gain, 0.4-degree differential phase, and all outputs can drive ac-or dc-coupled 75 M-ohm loads with switchable gain of 0 dB or 6 dB for flexibility. The chip sets dc C Clamp levels of 250 mV and/or 1.125 V, depending on the type of input signal. The 2:1 multiplex is designed for the YpbPr/RGB or YpbPr/YC-CV inputs found in a number of video applications.
The FMS6407 chip's three selectable frequencies address industry standards: 8 MHz capability for interlaced (i) standard definition 480i; 15 MHz is for progressive (480p); and 30 MHz for 720p and 1080i HDTV. The bypass mode in the chip provides upward compatibility for PCs and allows engineers to develop circuitry for the newest HDTV approach, 1080p, with their own external discrete filters while the specifications are being finalized.
The 20-pin TSSOP-20 package eliminates about 90 discrete components that all together can take up to 2,500 mm2 of board space and reduces that board space to a 6.5 × 6.4 mm2 area that is only 1.2m thick.
Target applications engineers designed the FMS6407 for include among other things, cable and satellite set top boxes, DVD players, HDTV, personal video recorders, and Video on Demand.