For many years TV’s used ‘canned’ tuners. These were analog electrical components mounted on PCBs then wrapped in tin cans. These ‘tuners’ were the RF sub-system of your traditional TV. In terms of size they are about the size of your index finger.
You connected your antenna to the input of your TV, which is the input to the can, tuned your device (tuned the can) and the device received the radio frequency and handled all the magic related to extracting the sound and images being broadcast. They did one job exceptionally well.
Canned tuners are no more, technology marches on.
The industry re-invented itself in the early 2000’s and shrunk those metal cans down into single integrated circuits (chips). See the picture above. Silicon tuners today are significantly smaller, around the size of your finger nail!
Analog TV image quality from those early silicon tuners was deemed questionable by some, and rightly so, but the writing was clearly on the wall for the legacy canned technology. The Silicon Valley micro-chip companies were out to re-invent TV tuning technology.
If you’re interested in the science behind TV RF tuners, canned and silicon, how they manipulate and select RF, then you’ll like this document courtesy of FreeScale Semiconductors.
Fair warning, the document is a little dated but still gives a great overview of the basic problem space of mixing, down conversion, LNAs and AGC. The document goes on to describe how two of FreeScales particular products attempt to solve those issues.
While I don’t recommend using FreeScale tuners today, I’m happy to recommend this introductory document.
Copyright © 2015 Steven Toth