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INA901-SP: Maximum Input Current 5mA on Input Pin

Wes Clow
Prodigy 40 points
Part Number: INA901-SP

I have an application that will input more than 5mA into the IN+ and IN- pins of the INA901-SP. Do I need to add external resistors to decrease the input current below the absolute max stated in the datasheet? Due to offset errors with two individual resistors I assume I would need to get two resistors on the same die. What is the best way to solve this issue?

  • +1
    Prodigy 40 points

    From TI:

    Hello,

    The 5mA input current limit is a bit of a misnomer in this circumstance. The voltage ratings of the part are more relevant for your use case because they describe the external stresses the part is designed for. The 5mA limit is more frequently used to describe the limits if you exceed to voltage rating, e.g. "if you operate the input pins at 70V the device will remain undamaged if you limit the current to 5mA" This shouldn't be an issue for regular operating conditions since the input bias current for the input pins is limited to ±8µA.

    The device is shown in figure 10 sourcing up to 32mA of current when short-circuited, so the device can certainly take more than 5mA on the power supply pin when it is operated in normal voltage ranges (2.7-16V) and the 5mA limit is probably meant to apply to voltages outside of this range.

    So in summary, if you limit the voltage on the pins to the rated conditions you don't need to worry about the 5mA limit because the device is designed for these voltages and will never draw more current than it can handle.

    Let me know if you need any additional clarification on this issue,

    Levi DeVries