Photodiode noise cancelling, how to?

[schmitt trigger]

A simple FM modulator may be done with the VCO section of a CD4046. The timing capacitor and resistor should be of low Tempco and the supply voltage regulated for low drift.

 

[neazoi]

A simple FM modulator may be done with the VCO section of a CD4046. The timing capacitor and resistor should be of low Tempco and the supply voltage regulated for low drift.

Can you give a schematic for it please?

 

[betwixt]

Look at:

http://www.maxmcarter.com/lasrstuf/lasermodulator.html

not exactly as I would have done it but it demonstrates the principle. If you use a PLL demodulator you should get even better SNR.

Brian.

 

[neazoi]

Look at:

http://www.maxmcarter.com/lasrstuf/lasermodulator.html

not exactly as I would have done it but it demonstrates the principle. If you use a PLL demodulator you should get even better SNR.

Brian.

Thanks in advance!