Other Parts Discussed in Thread: TINA-TI
Hi I'm new in this forum
I'm not very good at english, I've searched about transimpedance amplifiers to read a quad photodiode, I'm using the basic circuit only using a feedback resistor to amplify the current to voltage with photoconductive mode connecting the cathode to ground. When I connect only one photodiode the output is near to the desired voltage value, in this case -3.3 V or 670 uA x 4.7k ohms, but when i connect one more photodiode the output drops to -2.8 V, connecting the fourth photodiode the output voltage drops to -2.2 V. What could be the reason why the voltage drops when connecting more photodiodes?
Thanks.