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INA240-Q1: Bias current: which direction and how much max and min value?

Part Number: INA240-Q1
Other Parts Discussed in Thread: INA190, INA191, INA186, INA240

Hi team, 

About its bias current: which direction does it flow (sink or source to IN+/IN-) and how much max and min value? Datasheet says just 90uA type.

In addition, do you have any idea or example circuit to cancel this bias current by external circuit?
I would like to compensate its output error voltage.


  • Hi Ochi,

    The direction of the bias current is flowing into the IN+/IN- pins. Under datasheet condition, ±20% variation can be used as guidelines for min/max, which corresponds to 72uA and 108uA respectively. Though for a given device the two Ibs’ match very closely, you won't see such large variation.

    As you’re probably aware the bias current varies with common mode and differential input voltage according to the following curves:


    I’m not aware of an example circuit that cancels bias current, but it may be possible to calibrate for Ib. However, unless the current being measured is comparable to Ib, or there are significant exertional input resistances, there is no need to do so.

    We also have devices with very low input bias current(nA) such as INA186 and INA190/INA191 family. If the rest of the specs fit, one of these devices may help alleviate the worry for Ib.   

    Regards, Guang

  • Hi Ochi,

    provided the output of INA240 is read by an ADC, I would try to do it in the software. Or better take an INA with much lower specified input bias current.