mettiblack72
Junior Member level 1
Hello
TIA = transimpedence
I have lots of photodiodes for barrier detection , I tested one photodiode with one TIA op amp , and it was OK
1) Now I want to multiplex multiple photodiodes for my project , and I use 74HC4051 IC for that , I read in datasheet that between each of inputs to output 60 Ohm resistor , what's the affect of this resistor ?
2) I read this application note for TIA pcb design , and in this article author implied that the photodiode should be as close as possible to TIA because of the very low current of photodiode and TIA input bias current , It's very good for one photodiode , But when I use multiple photodiodes , I'm forced to place some photodiodes far away from TIA (40 photodiodes) , what should I do for this in circuit design ?
TIA = transimpedence
I have lots of photodiodes for barrier detection , I tested one photodiode with one TIA op amp , and it was OK
1) Now I want to multiplex multiple photodiodes for my project , and I use 74HC4051 IC for that , I read in datasheet that between each of inputs to output 60 Ohm resistor , what's the affect of this resistor ?
2) I read this application note for TIA pcb design , and in this article author implied that the photodiode should be as close as possible to TIA because of the very low current of photodiode and TIA input bias current , It's very good for one photodiode , But when I use multiple photodiodes , I'm forced to place some photodiodes far away from TIA (40 photodiodes) , what should I do for this in circuit design ?