lock-in amplifier AD630

Thread Starter

przemmo

Joined Jan 6, 2009
8
I want to use this part to detect low fluorescence over the human skin surface. Has anyone worked with the modulator/demodulator? Will I meet any problem?
For example simple circuit from the application note of AD630 (please find the jpeg)? I want to replace the bridge and instr. apm. with a light-to-voltage transducer with a gain stage. Do I need any phase shifter to adapt the phase of the gain stage to the reference generator signal?
 

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KMoffett

Joined Dec 19, 2007
2,918
Perhaps you could post the schematic of the front end you want to add. Otherwise, it's impossible to determine if a specific circuit creates a phase inversion problem. The more information you provide, the more likely you are to get a practical answer.

Ken
 

Thread Starter

przemmo

Joined Jan 6, 2009
8
Phase inversion is one phase shift is something other. What I want to ask is if I have to tune the phase of the signal to the phase of generator used. Every amplifier, even cables creates some phase shift. I want to know if this is a problem or it's neglegible shift. The front end is just a photodiode with transimpedance amplifier (feedback resistor say 10-50Mohms) connected to the AD630.
 
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