Hi All,
Please, I need some help.
Currently, I am working on a project. I need to design and make a circuit which will have two channels. I have two photodiodes. I have one laser beam. I split it into two equal beams and then I measure their intensities by using two photodiodes. Next, I use chopper to modulate second beam. I measure two signals simultaneously. My circuit has two outputs. One is a reference(just first beam). Second is a difference between two beams. Difference output works well. However, the reference channel gives me constant potential in -2.3V + some tiny reaction on light.
Photodiodes are connected between PAD1 and PAD2, Pad3 and PAD5
See attached scheme. There are few additional comments and my observations.
Additional information: I have already made prototype. Currently, I am testing it.
Part numbers:
Op. Amplifier: ADA 4817-1
photodiode: Hamamatsu S3071
Regards,
Plantis
Please, I need some help.
Currently, I am working on a project. I need to design and make a circuit which will have two channels. I have two photodiodes. I have one laser beam. I split it into two equal beams and then I measure their intensities by using two photodiodes. Next, I use chopper to modulate second beam. I measure two signals simultaneously. My circuit has two outputs. One is a reference(just first beam). Second is a difference between two beams. Difference output works well. However, the reference channel gives me constant potential in -2.3V + some tiny reaction on light.
Photodiodes are connected between PAD1 and PAD2, Pad3 and PAD5
See attached scheme. There are few additional comments and my observations.
Additional information: I have already made prototype. Currently, I am testing it.
Part numbers:
Op. Amplifier: ADA 4817-1
photodiode: Hamamatsu S3071
Regards,
Plantis
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