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OPT101: Sensor linearity

Anders Torsein
Prodigy 110 points
Part Number: OPT101

Hi,

The data sheet for OPT101 states that sensor nonlinearity is typically  +/- 0.01 % of FS. Is there any more data that you can supply me with regarding the nonlinearity?

Is the deviation always larger at high input signal or low input signal? Do you have any data regarding how the error is distributed?

The error is given as percentage of FS, the value is measured at 24V supply voltage. Is the deviation (in V) scaled linearily with the supply voltage (i.e. 12V supply voltage leads to half the error in V compared to the error in V at 24V supply voltage)?

Is the linearity error the same in % regardless of if feedback resistor (between "Output"-pin and "-In"-pin) is used or not (i.e. if supply voltage is 24V is linearity expected to be 2,4 mV if no feedback resistor is used, if feedback resistor do lead to 1/2 voltage is the linearity error 1,2 mV)?

 
The error is given as a typical value, is it possible to say something regarding worst case condition? Are there any measurements regarding spread of error?

In the actual case that I am working with is the ambient temperature stable at 26 *C, and thus are variations due to temperature not of interest.

Thanks in advance for clarification!

     best regards

              Anders T

  • 0
    TI__Mastermind 25895 points
    Hi Anders,

    I will need to check into this. I am in training all of this week so my responses may be delayed, but I should be able to get back to you by early next week.

    Best,

    Alex
  • 0 in reply to Alex Bhandari-Young
    Prodigy 110 points

    Hi Alex,

    Have you been able to get some information regarding the linearity of the OPT101-sensor?

       best regards

                Anders T

  • 0 in reply to Anders Torsein
    TI__Mastermind 25895 points
    Hi Anders,

    My apologies for the delay, and thanks for following up. You are correct that the +/- 0.01 % of FS linearity spec is a typical value. However, there is some additional information in the Linearity Performance section of the datasheet.

    "Nonlinearity remains less than approximately 0.05% for photodiode currents less than 100-μA. The photodiode is able to produce output currents of 1 mA or greater with high radiant power, but nonlinearity increases to several percent in this region."

    Best,

    Alex
  • 0 in reply to Alex Bhandari-Young
    Prodigy 110 points

    Hi Alex,

    Thanks for the response.

    In the actual design is the diode current less than 20 uA.

    Is there any more information regarding sensor linearity (outside of data available in the data sheet)?

    Is it expected that the linearity is better (or worse) at lower supply voltages?

    Please do review my initial questions, let me know if anything is unclear.

         best regards

                 Anders