Visible light communication using photodiode receiver

Question

I am designing a receiver circuit using photodiode with visible light communication application, analog signal I read with ADC of esp8266.

The circuit below is my design with a TIA and amplifier. Is there a bug?

I want to catch the light with 1-7 kHz frequency.

score 5 · Answer 1 · answered Apr 26 '23 at 16:53

5

Don't know if there is a bug

There are at least two.

When working properly, the output voltage of U2B will be negative. But U2 can't produce negative outputs without a negative power supply.
U2A is working as a comparator, but the range of reference voltages provided by VR1 is 0 to 5 V. Comparing this with the negative output voltage of U2B will always result in a low output.

answered Apr 26 '23 at 16:53

The Photon

Can you help me fix this design completely, I don't know too much about this knowledge – Shu Apr 26 '23 at 19:06
@Shu, I would re-design the first stage to one of the cofigurations that doesn't generate a negative output. – The Photon Apr 26 '23 at 19:08
I found this design in another project, somehow it still works well and the result is quite workable. – Shu Apr 26 '23 at 19:13
How not to produce negative output at U2B – Shu Apr 26 '23 at 19:15

1 Answers1