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I am looking at purchasing a 14-bit ADC chip (http://www.farnell.com/datasheets/1882573.pdf) for a battery monitoring project that I am working on, and am using a differential amplifier measuring voltage across a current shunt and then feeding that into an ADC.

Would this potentially work if I just used the output of the diff amp (1-5V) and into the +in pin and ground into the -in pin? If not, why not?

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Would this potentially work if I just used the output of the diff amp (1-5V) and ground into the +in and -in pins? If not, why not?

What you have said above makes no sense - with both input pins grounded, the device won't work. Probably what you want is reassurance that the device can work single-ended (as per your question title. The data sheet quotes this: -

For single-ended operation, the > non-inverting input (+IN) of the ADC141S626 can be driven with a signal that has a peak-to-peak range that is equal to or less than (2x VREF). The inverting input (−IN) should be biased at a stable VCM that is halfway between these maximum and minimum values. In order to utilize the entire dynamic range of the ADC141S626, VREF is limited to VA / 2. This allows +IN a maximum swing range of ground to VA. Figure 40 shows the ADC141S626 being driven by a full-scale single-ended source.

This is on page 16.

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  • \$\begingroup\$ sorry that was poor phrasing, what I meant was output of the diff amp into the +in and ground into the -in. \$\endgroup\$ – ElecEnthusiast Mar 10 '15 at 12:08
  • \$\begingroup\$ I did read that section actually, I should have been more succinct in my question. What I was trying to attain more was can I expect normal operation just by applying my signal into the inputs (single-ended as it may be), or if not, is there a way to use a differential input from my measurement somehow? \$\endgroup\$ – ElecEnthusiast Mar 10 '15 at 12:17
  • \$\begingroup\$ As is probably apparent, I am not fully savvy with ADCs, and didn't fully understand that section that you quoted. Would it be correct to say that with a Vref of 5V and a diff input, the ADC could read values from -5V to 5V? \$\endgroup\$ – ElecEnthusiast Mar 10 '15 at 12:32
  • \$\begingroup\$ Using the method in the data sheet should be ok but there might be a slight increase in noise on the digital values converted. \$\endgroup\$ – Andy aka Mar 10 '15 at 12:32
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    \$\begingroup\$ Look at figure 41 and figure 42. Neither input should go below 0V - inputs need to be biased positively - it is not a true bipolar differential input. \$\endgroup\$ – Andy aka Mar 10 '15 at 12:46

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