JPPoulin
Newbie level 6
Hello everyone,
We need to construct a very low cost circuit that need to sense a scene about 4-7 meters away the maximum amount of information available through photonic sensors at various bands (visible light, infrared, ultraviolet)
All of these photon sensors are available as photodiodes or phototransistors... Given that we need to amplify each of these with an OpAmp in logarithmic amplification and that we wish to keep that part of the circuit under $3 for 8 channels, do you think we should opt for a design based on photodiodes or phototransistors? (The circuit needs to be physically small)
Because of our cost constraint, my intuition tells me we’re better off with phototransistors in order to use the lower-cost OpAmps, but perhaps they greatly reduce the signal-to-noise ratio and we’re better off with photodiodes? (We need to amplify the signal for a standard ADC attached to a voltage rail of 1.8V and obtain the best possible dynamic range and signal-to-noise ratio)
Any recommendation on a decent type of OpAmp and the amplification topology to use would be greatly appreciated!
Thank you!
Jean-Pierre
We need to construct a very low cost circuit that need to sense a scene about 4-7 meters away the maximum amount of information available through photonic sensors at various bands (visible light, infrared, ultraviolet)
All of these photon sensors are available as photodiodes or phototransistors... Given that we need to amplify each of these with an OpAmp in logarithmic amplification and that we wish to keep that part of the circuit under $3 for 8 channels, do you think we should opt for a design based on photodiodes or phototransistors? (The circuit needs to be physically small)
Because of our cost constraint, my intuition tells me we’re better off with phototransistors in order to use the lower-cost OpAmps, but perhaps they greatly reduce the signal-to-noise ratio and we’re better off with photodiodes? (We need to amplify the signal for a standard ADC attached to a voltage rail of 1.8V and obtain the best possible dynamic range and signal-to-noise ratio)
Any recommendation on a decent type of OpAmp and the amplification topology to use would be greatly appreciated!
Thank you!
Jean-Pierre
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