Showing posts with label hack. Show all posts
Showing posts with label hack. Show all posts

22 February 2008

More on the Mystery CCD

Yesterday I posted about a mystery CCD that I found in a flatbed scanner. It has no part number on it; all I knew was that it has 22-pins. I was hoping that it was like an LCD module---multiple vendors but a single footprint. Sadly, this is not the case.

Proof by counterexample: Toshiba produces at least two 22-DIP CCDs with incompatible footprints: the TCD1707D and the TCD2905D. From my analysis below, I now know that this CCD is neither of those.

I pulled out the continuity tested and started tracing connections. Here's what I've found:

  1. GND
  2. GND
  3. buffered input 1
  4. GND
  5. buffered output 1
  6. +12V
  7. GND
  8. buffered input 2
  9. buffered input 2 (8 and 9 are the same)
  10. GND
  11. GND
  12. GND
  13. odd, see below
  14. buffered input 3
  15. +12V
  16. GND
  17. buffered output 2
  18. buffered output 3
  19. GND
  20. buffered input 4
  21. GND
  22. GND
By "buffered input," I mean that the pin is driven by a 74HC04 inverted, through a resistor. By "buffered output," I mean that the pin is fed into a simple transistor inverter. By "odd", I mean that two '04 inverters are put in series and drive themselves through a capacitor. The output also drives this pin through a resistor.

Since this device has three outputs, I infer this is a color CCD. I suppose I could have read the packaging on the scanner, but I threw it out before I thought to check.

21 February 2008

Mystery CCD: Help me identify this part

Mystery CCDI pulled this out of a flatbed scanner. It's a linear charge-coupled device (CCD). I want to use it in a project (see below), but I don't have any datasheet. All I know is that it has 22 pins. Any pointers would be greatly appreciated.

So what do I want to use it for? I want to put it next to a radioactive mass and use it to generate truly random numbers.