The next time you sit down to watch the baseball playoffs or get caught up on the latest news, stop and think about your television for a minute. What if you were to take all those components, all those wires, and all those connections, shrink them down, and put them on one piece of silicon?
At first glance, it’s hard to imagine. But if you think about it, it's possible to do.
Fiber optic cable connections that provide TV and Internet could profit from higher levels of integration. In some cases, the fiber cable comes right into your house. In other cases, it stops at the street and the medium changes from fiber optic to coaxial cable. In both cases, there is a box full of electronics that does massive amounts of signal processing.
Wherever the fiber optic cable has its termination point, there will be an optical receiving device such as a photo diode; that will be followed by a transconductance (or perhaps a transresistance) amplifier. Since this is a duplex system, there will also be a laser diode and its associated driver.
The driver, of course, contains an output capable of sourcing current in the range of a few hundred mA to an amp or two (pulsed). There is also feedback circuitry to regulate the output accurately and possibly to monitor the laser diode's temperature.
If there is a coaxial cable link to the house, then we need driver and receiver circuitry. If we stop right there, we have plenty that we could try to push into one piece of silicon. Is that possible? Practical?
If the fiber optic cable comes right into the house, then everything described above would be in what's commonly referred to as the set-top box. But there's more, of course. There will be significant digital processing to encode and decode all the data that's coming and going. Then more data processing to turn massive data streams into both individual TV channels and a modem for the Internet: for the TV channels, some interface circuitry to generate HDMI; for the Internet, a router/WiFi port.
Does anyone still need baseband audio and composite video? Possibly, so we might as well add the decoder circuitry and a couple of op-amps for the analog audio and video.
Additional subsystems needed include an IR receiver for the TV remote and miscellaneous power supply support.
So, how shall we partition all of this? And how much can be squeezed onto one slab of silicon? Let us know your thoughts on the partitioning. Have you worked on any of the subsystems described here such as HDMI or laser drivers? What design problems did you deal with?