Supplying 0-5V

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hinovel
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Joined: Wed Aug 15, 2018 1:34 pm

Supplying 0-5V

Post by hinovel » Wed Sep 12, 2018 8:55 am

I’m trying to supply a range of 0-5V through a pressure transducer to my ADC-20 board. I was hoping there was a way to systematically reduce the output of the pressure transducer by 2.5V to make sure the board is in the acceptable -2.5V to 2.5V range. Possibly by hooking up the output of my transducer in series with the 2.5V pin to effectively subtract that value across my transducer output?
I’d rather not use a potential divider as this would give me a 0-2.5V range and effectively double my error.

Gerry
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Joined: Mon Aug 11, 2014 11:14 am

Re: Supplying 0-5V

Post by Gerry » Wed Sep 12, 2018 2:31 pm

Hi hinovel,

Could you let us know exactly what you are trying to measure and what your measurement goal is (what is the smallest difference in pressure that you need to be able to detect, and how much error can you tolerate between what the measured/converted value is and what the true pressure is?). Could you also tell us how you are powering the pressure sensor (e.g. bench supply with/without floating outputs, battery, etc) and exactly what type of pressure sensor it is?

For the record, using 0 to +2.5V instead of -2.5 to +2.5V, affects the resolution (or precision) of the measurement (and only marginally), rather than the accuracy. As the ADC-20 can give you 18-bits to 20-bits of resolution, half the input range means that you would only lose 1 bit, leaving 17-bits to 19-bits of resolution. The actual precision of the resistor values used, however, will significantly affect the accuracy.

Regards,

Gerry
Gerry
Technical Specialist

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