Burr-Brown Corporation announced the PLL1700, a high performance/low cost, multi-clock generator Phase Lock Loop (PLL) used to synchronize audio and video clocks within DVD (Digital Versatile Disc) systems.

It is important in systems containing both digital audio and digital videoýDVD players, DVD add-on cards for multimedia PCs, digital HDTV (High Definition Television), broadcast applications, and set-top boxesýthat the clocks be properly synchronized. Without proper synchronization, the voice/picture correlation can be poor and very noticeable to the observer.

The PLL1700 achieves audio/video synchronization by accepting a 27MHz MPEG-2 video clock and derives all of the audio clocks for the rest of the system. MPEG-2 (Moving Picture Experts Group) systems require several clocks to control the surround sound AC-3 decoder, digital signal processor, and digital-to-analog converter(s). MPEG-2 is the leading international standard for the coding and synchronization of moving pictures and audio.

"The PLL1700 is a support product to be used with our 24-bit, 96kHz digital-to-analog converters in MPEG-2 based applications such as DVD. This device contains a very high performance analog PLL with 150ps of clock jitter and zero PPM error, meaning that the output clock frequencies are perfectly accurate," said Mike Centorino, audio product marketing manager at Burr-Brown. "In addition to synchronizing audio and video clocks, the PLL1700 gives designers both cost and space savings by eliminating external components that would be needed in order to achieve this high level of performance."

According to In-Stat, worldwide shipments for DVD players were 700,000 units in 1997 with a forecast of over 19 million units in 2001.

The device features a 27MHz master clock input, generates several audio clock frequency outputs, has low clock jitter (150ps), zero PPM error, +3.3V CMOS logic interface, and dual power supplies (+5V and +3.3V).

Burr-Brown continues its push into the consumer arena by making another worthwhile product step for the DVD and other digital video OEM markets. 27 MHz is a magic number in video, representing one of the only levels of international agreement ever made in the industry. Whether you are in either of the previous 525/59.9 or 625/50 markets D-1 is all at 27 MHz.(2 x 13.5 MHz.) Every product that wants to lock the audio chain to the digital video will be required to produce those audio clocks from the video reference and this part is extremely timely for that expansion. First generation products -- and sloppy ones, like my DBS satellite receiver! -- lack this provision and the lack of synchronization is frustrating.

So, in addition to the huge market in DVD players there will also be a demand for this part from the manufacturers of digital conversion boxes -- as the terrestrial DTV market starts up -- and from the cable set top boxes, and next generation satellite receivers. The only frustration that I can imagine will be expressed by most OEM designers is "why dual supplies? The part is certainly not overpriced.

The PLL1700 is in production in a 20-pin SSOP and is priced at $1.95 in 1000-piece lots.