programable analog threshold network: was RE: [sdiy] new project in the works

[Czech Martin]

thermometer code:
each bit represents one step of the ladder
whereby the lower significant bits are always
on up to the top bit.

i.e. step 1: only bit 1
     step 2: bit 1 and 2
     step 3: bit 1 and 2 and 3
     step n: bit 1 and... and bit n-1 and bit n

If you look at a LED representation of the code bits,
it is easy to understand why it is called thermometer code.
It is the natural way in which bits fall out of a flash ADC.

For our purpose we have to change that into a "one out of n code".
Because we need to select one single output step for each input step.
Such a network is called priority decoder.
Input bits in thermometer code disable all lower priority bits.
This is the point where glitches will come into play.

I will try to scan a scetch schematic this noon.


m.c.