Dear fellows,
I am trying to design a readout circuit of SiPM for ToF. The first stage is TIA circuit using OPA855 (gain 50ohm) and tested okay.
The thing is, due to the application requirement, I need to get the signal amplified by different scale. And due to space constraint, I cannot use multiple sensors.
So, I want 3 second-stages in parallel, with the gain of ~1x, 5x, 20x .
My question is how do I couple 3 amplification with the same first stage? Is there a standard procedure for this kind of design?
I tried to simulate using Tina, but it generates errors.
