I want to make a little camera out of discrete phototransistors - a 16x16 or 32x32 array, and am kind of at loss on how to read it out.
The initial idea was to have each row share a collector and every column to share an emitter, and to have a row mux above and a column mux below, heading into the amp/adc.
However, a few tests revealed that a mux like 74HC4067 is way too leaky for such a use (uCurrent is great!), at any decent sensitivity, with leakage current in low microamps.
I looked around, and there are low-leakage muxes like ADG732, but at painful prices and i'll need two of them per array.
So, the questions are - would a design like that work, is there a better way to do it, do both muxes need to be low-leakage, any other ideas?
![](http://i.imgur.com/YsOdacW.png)