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flotulopex
- 20th July 2015, 08:36
Hello,

I'm wondering if it is possible to implement an ADC knowing the analog input has no connection to the PIC's VDD & VSS.

Is this possible?
aratti
- 20th July 2015, 09:13
Is doable using a galvanic isolator.

Cheers

Al.
flotulopex
- 20th July 2015, 09:28
You mean something like a DC-DC converter?
aratti
- 20th July 2015, 09:38
No! Something like the Texas component slyt211. But there are several others doing the same job.

Cheers

Al.
flotulopex
- 20th July 2015, 10:31
...but, the SLYT211 is a (miniature) DC-DC converter (http://www.ti.com/lit/an/slyt211/slyt211.pdf) or am I missing something? :confused:
Acetronics2
- 20th July 2015, 10:32
Much simpler would be an external V/F converter that can be close to the source ( LM331 as an oldie ! ) http://www12.fairchildsemi.com/ds/KA/KA331.pdf then an opto-coupler :
you then just have to measure the incoming frequency ...

Alain
aratti
- 20th July 2015, 10:59
It is a galvanic isolator. It is also a DC-DC converter but this is just semantic. You need primarely a galvanic isolation.

Alain suggestion to use a voltage to frequency converter, is an interesting and cheap approch!

Cheers

Al.
flotulopex
- 20th July 2015, 13:33
Thanks for all the suggestions.

I never tried a V/F.

I'll give it a try :)