In the world of consumer electronics, one key factor can determine the commercial success or failure of a product: the bill of materials, or BOM. With a digital TV, the bulk of the BOM comes from embedded components, including power supply, pc board, key functional blocks, peripheral components and the enclosure itself. But highly integrated systems-on-chip (SoCs) can help drive down the cost of all of these elements-and help deliver a more palatable price point for the consumer.
Seven years ago, a typical entry-level digital TV set-top box contained more than 25 ICs with a cost of more than $200. An equivalent design in 2003 uses about seven ICs, with a cost of less than $50. Most of this cost reduction is the direct result of integrating functions on smaller-geometry silicon processes. In 1996, most DTV ASICs were designed and fabricated on 0.35-micron CMOS or greater. Currently, production DTV processor ICs are fabricated on 0.18-micron CMOS, with some new designs potentially using 0.13-micron processes.
SoC integration naturally results in physically smaller designs. Compare an old set-top box with the newest prototypes using SoC technology: SoC-based designs use about 20 percent of the area of a typical first-generation set-top box and approximately 80 percent of the area of a current, non-SoC design. With SoC-based designs, large motherboards are eliminated and set-top boxes-increasingly small and unobtrusive-can easily be attached to the side or even the rear of a digital TV.
Further material cost reductions-which can only help the North American rollout of DTV-will be achieved through single-chip RF solutions with simple, low-cost application circuits.
And, development costs and cycle times will be reduced when proven, open-standard, well-supported operating systems are adopted. Companies that use their core skills in these areas, and in advanced SoC design, will help OEMs drive down costs and consumer prices.
Paul Fellows is director of DTV systems-on-chip at Zarlink Semiconductor (Ottawa, Canada).
