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INA260: How do you correctly connect a solar panel to INA260 for measuring soiling on solar panels?

Ismael Anaya
Prodigy 10 points
Part Number: INA260
Other Parts Discussed in Thread: INA228, INA238

Hi, I am currently working on a prototype for estimating losses in solar panels due to soiling. However, I am confused about the correct way to connect the solar panel to INA260 to measure the ISC that will allow me to obtain accurate and reliable measurements. Please see the attached images and provide me with guidance on the correct connection for this project, as I am not sure if I should use an external shunt resistor for this measurement.

The panel I am using is a 30W panel, with an ISC of 1.83A.

  • 0
    TI__Intellectual 1235 points

    Hi Ismael,

    Option 1 would be the best option for measuring ISC.

    However, there are some considerations to take into account when measuring this way. 

    1) Since the inputs are floating in this configuration, it may take longer for the input to settle to a stable value.

    You may want to try grounding the negative input pin to the DUT ground, and see how the measurement behaves in this configuration versus with floating inputs. Then disconnect the DUT ground from the input pin after the ISC test is complete. 

    2) The total shunt resistance of the INA260 will be the integrated shunt resistance (2mOhm) and the package resistance (typically ~4.5Ohm according to the datasheet). However, the package resistance can vary an unspecified amount per device. Since you are measuring a short circuit with no additional load resistance, this variance in resistance could be an issue.

    To tighten this tolerance, you may consider a non-integrated shunt current sensor such as the INA228/INA238. This way the system current is only traveling through the shunt resistor you choose, not the INA package. 

    Cierra