The new chip, designated as BCM3510, is a combined VSB/QAM demodulator suitable for "cable-ready" digital TVs or set-tops.

Compared to its competitors' solutions, Broadcom's chip has already "proven significantly better VSB reception capabilities in the Advanced Television Systems Committee-sponsored field tests," claimed John Cooper, director of satellite and HDTV marketing at Broadcom.

Although this is Broadcom's first publicly announced VSB chip, the Irvine-based company said it is no stranger to the VSB market. With the new BCM3510, Broadcom engineers have enhanced the performance and features of the previously sampled but unannounced BCM3500, particularly in equalizer, gain control and adjacent and co-channel rejection. They also reduced the chip's power consumption to less than 1 watt, compared to 2.5 watts of BCM3500.

Using a 496 tap filter, Broadcom engineers opted for a brute force approach in their equalizer design to improve DTV reception performance. Both BCM3500 and BCM3510 are based on a full equalizer design, with its equalizer range extending from - 6 microseconds to + 40 ms to ensure reliable signal recovery in the harshest multipath environment. The chips are also integrated with a Broadcom-developed NTSC co-channel rejection system to minimize the signal loss experienced by traditional comb filter channel conditions.

The BCM3500 scored high marks in VSB reception capabilities during the Advanced Television Testing Center Grand Alliance System tests held some time ago, according to Cooper. The new BCM3510 maintains the same high-performing VSB reception characteristics, he added.

The BCM3510, fabricated using a 0.18 micron process, is in its late sampling stage, according to Cooper. "We expect to see it designed into a number of digital TV sets shown at the Consumer Electronics Show in January, 2001, and in products scheduled for market in mid 2001."

The equalizer design — used in BCM3500 and BCM3510 — was based on Broadcom's internal development. "The technology belongs to our core competency," said Cooper. The whole BCM3500 chip itself was developed in joint efforts with Sony Corp.

Cooper acknowledged that "controversies over the VSB modulation scheme, challenged by Sinclair Broadcast Group earlier this year, has put doubt in people's minds" on the current U.S. digital HDTV system. However, Cooper maintained that today's U.S. digital TV stalemate is not a product of technical debates over modulation schemes, stemming instead from larger issues other than DTV reception problems. Those unresolved issues, he cited, include that "there is no revenue benefit for broadcasters" to move onto HDTV broadcasting and "consumer electronics manufacturers are slow to roll out HDTV-capable systems."

Cooper holds high hopes for Federal Communications Commission chairman William Kennard's latest proposal, in which the chairman asked Congress to require all new TV sets to receive digital TV programming by 2003. "This should push forward" a speedier roll-out of more digital TV sets on the market, Cooper said. In a recent speech, the FCC chairman also called for Congress to impose a "spectrum squatters fee" on broadcasters who fail to complete the conversion to digital broadcasts by 2006.

Broadcom's BCM3510, priced at $20 in 10,000 piece quantities, is available in sample quantities now. Broadcom already offers on the market BCM7020, an MPEG-2 main profile at high level decoder IC integrated with a 2D/3D graphics subsystem for SDTV and HDTV displays. To enable complete HDTV system development with the BCM3510 and BCM7020, Broadcom provides reference designs with complete software source code, schematics and Gerber files.