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AD5248 2.5 kOhms characteristics

I need an accurate resistor  with more than 256 Steps. Thats no problem by using the AD5248. I can connect the two potentiometer/ or rheostaten with some other resisors. I dont want describe the circuit i'm using more precisenlty.

I'm interested in the Stepsize, the wiperresistance und the max. resistant of the AD5248 2.5 kOhm version. In the Datasheet, there is just described the 10 kOhm variant. I would be proud of some Information of the 2.5 kOhm variant.

As i sayed further, i need an accurate systhem. The tollerance of 20 percent aren't what i'm searching for, but there is no better component, so i must handle that. Does the tollerance describe the behavior of the AD5248 or an static devitacion of each single component ?

thank you for each help

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  • Hi Felix,

    The wiper resistance that you are measuring is still within specifications as it is smaller compared to the maximum of 200 ohms.

    LSB is the ideal step resistance which is ~9.76ohms for the 2.5k variant. The R-DNL specification is the error on these LSB. Ideally the step size is equivalent to 1 LSB but due to DNL in the resistance, the error on the step can be as much as 2 LSBs or ~19.53ohms. So the 3ohm step size that you are encountering in your setup is still within specifications.

    We currently don't have a potentiometer/rheostat solution that have a 3ohm or lower step size. Can you provide a simplified schematic of your application so that we could have a better understanding of what you are trying to do and provide a better solution?

    Thanks and best regards,

    Rainier

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  • Hi Felix,

    The wiper resistance that you are measuring is still within specifications as it is smaller compared to the maximum of 200 ohms.

    LSB is the ideal step resistance which is ~9.76ohms for the 2.5k variant. The R-DNL specification is the error on these LSB. Ideally the step size is equivalent to 1 LSB but due to DNL in the resistance, the error on the step can be as much as 2 LSBs or ~19.53ohms. So the 3ohm step size that you are encountering in your setup is still within specifications.

    We currently don't have a potentiometer/rheostat solution that have a 3ohm or lower step size. Can you provide a simplified schematic of your application so that we could have a better understanding of what you are trying to do and provide a better solution?

    Thanks and best regards,

    Rainier

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