hey all,

i want to buffer a voltage between 2 DC circuits with different grounds. a traditional op amp buffer won't work as i am not prepared to connect the 2 grounds together. what i would want is something like an optocoupler but with linear characteristics. can anyone suggest a method for doing this ????? (the voltage that i want to buffer is in the range of 0V to 5V. the buffered voltage will actually be an analog input to a PIC).

thanks in advance !!!!!!!!!!!

 

Here is what I'm thinking about:
DC circuit 1 → V to F → Op Amp → optocoupler → F to V → Op Amp → PIC ADC port
DC circuit 2 → V to F → Op Amp → optocoupler → F to V → Op Amp → PIC ADC port

V to F - maybe 0~5V convert to 0~5Khz.
F to V - maybe 0~5Khz convert to 0~5V
Op Amp - Op Amp maybe is unnecessary, it depends on the final design.

 

You have some options. I give you some links here
http://www.ti.com/paramsearch/docs/...log&familyId=512&uiTemplateId=NODE_STRY_PGE_T
http://www.ti.com/lit/ds/symlink/til300.pdf
See if this fit your needs
Edit It looks like the TIL300 is obselete try this instead
http://www.vishay.com/optocouplers/list/product-83622/
http://www.vishay.com/docs/83708/appn50.pdf
http://datasheet.octopart.com/HCNR201-000E-Avago-datasheet-30849.pdf
HCNR200/201 is a just a IL300 in a wider package