Wireless high-definition video: silicon consolidation that's maximal
Brian Dipert -November 18, 2010
The Wireless Gigabit Alliance’s 60-GHz-based high-definition wireless-video-transport scheme may be on the way, but SiBeam’s pioneering approach and multiple product generations are already on the scene (see “The quest for robust wireless high-def video connections,” EDN, Sept 23, 2010, pg 32). Peer inside a SiBeam-developed reference design to see how the company accomplishes this hefty bit-rate trick, complete with support for 3-D video presentations and for equipment control and networking augmentations.
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1. Take off the top covers of the transmitter’s and receiver’s enclosures, and you’ll find that a USB (Universal Serial Bus)-interface PCB (printed-circuit board) takes up most of the internal space. This debugging and control board mates with PC-side software, and production-system designs won’t need it. Such designs can be substantially smaller, less costly, and more power-thrifty as a result.
2. Behind the units’ plastic front panels and underneath intermediary metal shields that block all but the transmitting and receiving antenna arrays are 22×125×6-mm PCBs containing the core circuitry for each device. In this case, too, however, some of the silicon content is exclusive to the evaluation task and won’t appear in a production design. To wit, the top sides of both the transmitter and the receiver modules include Atmel AT91SAM256 microcontrollers to implement stand-alone operation. In an end-customer design, such as a Blu-ray player, a set-top box, a television, or an integrated home-theater setup, the system processor will typically manage the module, making the dedicated microcontroller unnecessary.
3. SiBeam’s SB9220 HRTX (high-resolution-transmitter) WirelessHD (high-definition) network processor sits on the transmitter module’s top side. The SB9210 HRTX RF transceiver is alongside it and underneath a ceramic microantenna-array lid. Corresponding ICs on the receiver module’s top side are the SB9221 HRRX WirelessHD network processor and SB9211 HRRX (high-resolution-receiver) RF transceiver. These latest-generation chip sets handle 1080p-resolution video at 60-Hz frame rates, with color depth as high as 4:4:4. They also comprehend HDMI’s (high-definition multimedia interface’s) CEC (consumer-electronics-control) feature, as well as WVAN (wireless video-area network). WVAN support provides the ability for a video source, such as a PC or a game console, to automatically be aware of (and for its user to subsequently select among) various available destination display devices and for a user (at a destination display) to select among available video sources.
4. A California Micro Devices ESD (electrostatic-discharge)-protection chip clamps transients originating from the HDMI connector on the receiver module. The transmitter implements ESD protection for its TMDS (transition-minimized differential-signaling) lines using discrete components. In this case, the HDMI connector mounts on the module back. SiBeam also makes evaluation modules for LVDS (low-voltage differential signaling) and LVCMOS (low-voltage complementary-metal-oxide-semiconductor) video interfaces. Also visible on both modules’ backs are the power- and system-processor-control interfaces.