connectivityZONE Products for the week of October 8, 2007
Pericom Semiconductor Corporation Says…
Next Generation Technology for PCI Express & Digital Video Systems
PCI Express 2.0 and Display Port products meet the high-performance needs of next-generation computing and consumer platforms
Pericom Semiconductor Corporation has introduced an electrical Display Port-to-DVI/HDMI Bridge and a prototype of its PCI Express 2.0 (PCIe “Gen2”) ReDriver.
Pericom has a strong foundation in PCIe Gen1 (2.5 Gbits/s) with signal conditioners, signal switches, packet switches, PHY, bridging and timing solutions. The company has delivered PCIe Gen2 (5 Gbits/s) signal switch and clock generator products earlier this year with more Gen2 products in development, such as its Gen2 ReDriver prototype demonstrated at IDF. Pericom’s electrical Display Port-to-DVI/HDMI Bridge addresses the digital video market for the next generation of high-definition video interfaces.
“The adaptation of Display Port technology in PC graphics is already underway among major Desktop and Notebook PC manufacturers around the world,” said Brian O’Rourke, principal analyst at In-Stat. “Pericom’s latest electrical DP to DVI/HDMI Bridge will enable merging the latest DP video graphics to legacy DVI/HDMI monitor connectors.”
Display Port (DP) is a license-free digital audio/video interconnect standard (VESA 2007) used between computer and display monitor and widely supported by companies such as Intel, Nvidia, Dell, and HP. “Digital video is high in demand and DP is the latest digital video interface standard for PC digital display,” said Shaf Rahman, Pericom’s senior marketing director for Switch and Interface Solutions. “Existing protocols like HDMI, VGA and DVI dominate the market, and this is where our new electrical DP to HDMI/DVI Bridge comes in. It enables integrated translation within the PC, or externally (dongle adapter) between the PC and display unit. Our customers can develop with DP now, without worrying about interoperability to legacy and existing systems.”
Electrical DP to HDMI/DVI Bridge Key Features
- Converts 4-differential low-swing AC-coupled inputs to HDMI rev 1.3 compliant outputs
- 5V to 3.3V DDC and HPD level shifter
- HDMI level shifting operation up to 2.5 Gbits/s per lane (required for 36bit Deep Color)
- Integrated 50 Ohm termination resistors for AC coupled differential inputs
Pericom will preview its PCIe Gen2 ReDriver signal conditioning technology for servers, desktop and notebook PC applications at IDF along with other PCI Express solutions and the electrical DP to DVI/HDMI Bridge. This ReDriver technology will extend a 5- Gbit/s differential trace pair, minimizing bit error rate and restoring the original signal quality, thereby increasing system performance and reliability.
EN-Genius Says…
Both the DP-DVI/HDMI product and the soon-to-be released 5-Gbit/s Gen2 PCIe semi-product announced here are clear evidence that Pericom has put its expertise in analog and clock signaling to good use in the digital space. Over the past year, I’ve started seeing many more people using computer monitors as video displays, and I’d expect the once-firm boundary between which content is on what screen to continue to blur even further. This is an unmistakable sign that Pericom’s handy DisplayPort bridge will be a big hit in both computers and adapters. Given how long some computer equipment stays in the field (especially displays), I’d expect that they’ve got a chart-topping product on their hands for at least the next three to five years.
I also think that, once it is actually released, Pericom’s PCIe Gen2 ReDriver will enjoy similar popularity because it will help support PCIe SerDes technology as it is being pushed to do far more than was ever intended. That’s why I’ll devote the rest of the review to sharing what I learned about this handy little device.
Pericom says their soon-to-be released ReDriver will use a combination of equalization and other analog techniques to provide designers with four to eight lanes of inexpensive, low-power (100 mW/channel) signal clean-up and de-jitter at a fraction of the cost of a true CDR. If it works as-advertised, it will go a long way towards fixing the reach problems found in the transceivers of many ASICs and ASSPs which were designed to meet the 8 inch maximum reach of the basic PCIe Gen2 spec. For the many PC boards, backplanes and cables tasked to carry the signals much further, Pericom’s ability to drive up to 36 inches FR-4 and 48 inches of Cat-6 will be welcome indeed.
 Each of the ReDriver’s channels has a fixed-slope linear equalizer that can be set to any of eight gain levels ranging from 1.5 dB to 15.2 dB. The slope has been carefully chosen so that it provides the effect of compressing the signal to expand the sweet spot of a slim, noisy data eye into the main part of the signal (see Figures). On the transmit side its output amplitude will be programmable between 0.5 V and 1 V in four steps with an eight-step de-emphasis circuit that can be set between 0 dB to -8.5 dB.
 This would be enough for most chip makers to call a product but Pericom has gone the extra mile and added a few other features that improve performance and add value to the part. The slickest trick they’ve pulled off is adding an input threshold detection circuit which will keep the noise floor down by not amplifying signals below a certain level. The detector cut-off voltage is 120 mV so when it sees an input below that level, the device waits 10 UI to see if the signals swing any higher. If not, those signals will be killed, helping assure that noisy signals are not propagated through the ReDriver. It is also equipped with an output load detect circuit that automatically turns off unused channels to save power.
Since I’ve had some experience with other successful signal processing technologies , such as those from Analogix, National Semiconductor, and Quellan, I know that there is more than one way to get good signal integrity on a fast SerDes channel. With this in mind, I asked Pericom to share some of the key features that differentiate their ReDriver products from some of the other offerings.
Rather than risk losing something in translation, I’ll simply post Pericom’s responses here. In the interest of accuracy, I have deliberately avoided editing Pericom’s comments so please forgive the redundant discussion of equalization and de-emphasis in the first two paragraphs.
We looked at the product offerings from some of our competitors and tried to compare them on a technical basis, as much as possible.
- Pericom ReDrivers feature configurable output drive levels. This allows for adjustment beyond the industry standard specification to allow for system specific optimization. For example, output drive can be set to 0.8x, 1.0x, 1.2x or 1.4x the reference output level. Some of the companies we looked at offer a single setting for most of their products
- Pericom ReDrivers feature configurable output de-emphasis levels. Again, this allows for application-specific optimizations to ensure good quality signal delivered to the receiver. For example, de-emphasis can be set to 0, -2.5, -3.5, -4.5, -5.5, -6.5, -7.5 or -8.5 dB. Not all companies we looked at had this range of setting for their products
- Pericom ReDrivers will soon be available in wide, 8-channel configurations, whereas most companies offering advanced equalization only offer 4-channel devices.
- Pericom ReDrivers provide protocol-specific optimizations. For example, the noise floor is different for different standards. For PCIeG1 it is 175 mV, for PCIeG2 it is 120 mV and for SATA/SAS it is 200 mV. As a second example, the idle voltage pulls to Vdd for PCI Express, while it pulls to the output common voltage for SATA/SAS. Another example is the 6 variations of SATA spec (i,m,x with some variations between 1.5 and 3.0 Gbit/s). Matching the industry standard does provide the easiest design-in and best interoperability with other devices, and does provide the best operation and reliability of the overall system solution, as compared to generic, universal conditioners which do not account for these variations.
Pericom will be offering two versions of the same ReDriver chip. Their high-end eight channel device is housed in a 100-pin LFBGA package that brings out the lines that control the programmable pre-emphasis equalization and amplitude settings while their lower-cost series has settings that are fixed at the time of manufacture.
The PI3VDP411LS electrical Display Port-to-DVI/HDMI Bridge is in production and is offered in Pb-free packaging. Pricing is $1.50 in 10-k lots.
Pericom’s PCIe Gen2 ReDrivers will be available in mass production in Q1, 2008. While not final, 10K-piece pricing for the Re-Driver is expected to range from $1.25-$2.50/lane for PCIe Gen 2 applications, and as low as $1/lane for SATA-oriented products.
Data Sheet PI3VDP411LS
Data Sheet PI3VDP411LST
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