FPGA photon counter low voltage

[JCard]

Hi! I'm currently building a photon counter using the USB-7856R R series multi function rio. I have attached the labview program I'm using to count 1VPP square waves, and it works just fine. However, I eventually want to use it for photon counting, and our photon counter only outputs a signal of 200mV, which from what I understand is too low for any of the FPGA logic structures. Am I correct in this, and if so, is there any way to circumvent the issue?

Thank you!

[Kevin.MN]

Hi JCard,

You are correct on the digital logic levels. 200mV is too low for digital output. 

As I see it, there are two main routes forward (there may well be others).

1. Find a way to increase the voltage (e.g. amplifier)

2. Switch to analog input and count when the voltage exceeds a particular threshold. (Potentially helpful example)

Best of luck with the photon counting!